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Qin L, Yang P, Jin Q, Yang C, Zhang J, Yang Y. Real space method for HAADF image simulation. Micron 2024; 185:103686. [PMID: 38981387 DOI: 10.1016/j.micron.2024.103686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 06/30/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
A new real space HAADF simulation method was described in detail and a Real Space- STEM software was developed based on the new simulation method. The algorithm of the real space method can quickly calculate and simulate the microstructure images of complex crystals. The Real Space-STEM software developed in this paper has the functions of HRTEM and HAADF image simulation based on the real space method. By using this software to simulate high-resolution images of representative crystal materials from each crystal system, the HAADF images are both accurate and efficient. The effect of STEM parameters on HAADF imaging has been discussed using simulation results.
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Affiliation(s)
- Lufei Qin
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Pucheng Yang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Qianqian Jin
- Materials Science and Engineering Research Center, Guangxi University of Science and Technology, Liuzhou 545006, China.
| | - Chuanlong Yang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Jinpeng Zhang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Yi Yang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China.
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2
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Hu WT, Tian M, Wang YJ, Zhu YL. Moiré fringe imaging of heterostructures by scanning transmission electron microscopy. Micron 2024; 185:103679. [PMID: 38924906 DOI: 10.1016/j.micron.2024.103679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 06/03/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024]
Abstract
A heterostructured crystalline bilayer specimen is known to produce moiré fringes (MFs) in the conventional transmission electron microscopy (TEM). However, the understanding of how these patterns form in scanning transmission electron microscopy (STEM) remains limited. Here, we extended the double-scattering model to establish the imaging theory of MFs in STEM for a bilayer sample and applied this theory to successfully explain both experimental and simulated STEM images of a perovskite PbZrO3/SrTiO3 system. Our findings demonstrated that the wave vectors of electrons exiting from Layer-1 and their relative positions with the atomic columns of Layer-2 should be taken into account. The atomic column misalignment leads to a faster reduction in the intensity of the secondary scattering beam compared to the single scattering beam as the scattering angle increases. Consequently, the intensity distribution of MFs in the bright field (BF)-STEM can be still described as the product of two single atomic images. However, in high angle annular dark field (HAADF)-STEM, it is approximately described as the superposition of the two images. Our work not only fills a knowledge gap of MFs in incoherent imaging, but also emphasizes the importance of the coherent scattering restricted by the real space when analyzing the HAADF-STEM imaging.
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Affiliation(s)
- Wen-Tao Hu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China
| | - Min Tian
- Jihua Laboratory, Foshan 528200, China
| | - Yu-Jia Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China; School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016, China.
| | - Yin-Lian Zhu
- Bay Area Center for Electron Microscopy, Songshan Lake Materials Laboratory, Dongguan 523808, China; School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
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3
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Park CH, Lee H, Choi JS, Yun TG, Lim Y, Bae HB, Chung SY. Atomic-Level Observation of Potential-Dependent Variations at the Surface of an Oxide Catalyst during Oxygen Evolution Reaction. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2403392. [PMID: 39011793 DOI: 10.1002/adma.202403392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 07/07/2024] [Indexed: 07/17/2024]
Abstract
Understanding the intricate details of the surface atomic structure and composition of catalysts during the oxygen evolution reaction (OER) is crucial for developing catalysts with high stability in water electrolyzers. While many notable studies highlight surface amorphization and reconstruction, systematic analytical tracing of the catalyst surface as a function of overpotential remains elusive. Heteroepitaxial (001) films of chemically stable and lattice-oxygen-inactive LaCoO3 are thus utilized as a model catalyst to demonstrate a series of atomic-resolution observations of the film surface at different anodic potentials. The first key finding is that atoms at the surface are fairly dynamic even at lower overpotentials. Angstrom-scale atomic displacements within the perovskite framework are identified below a certain potential level. Another noteworthy feature is that amorphization (or paracrystallization) with no long-range order is finally induced at higher overpotentials. In particular, surface analyses consistently support that the oxidation of lattice oxygen is coupled with amorphous phase formation at the high potentials. Theoretical calculations also reveal an upward shift of oxygen 2p states toward the Fermi level, indicating enhanced lattice oxygen activation when atom displacement occurs more extensively. This study emphasizes that the degradation behavior of OER catalysts can distinctively vary depending on the overpotential level.
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Affiliation(s)
- Chang Hyun Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Hyungdoh Lee
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Jin-Seok Choi
- KAIST Analysis Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Tae Gyu Yun
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Younghwan Lim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Hyung Bin Bae
- KAIST Analysis Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Sung-Yoon Chung
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
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4
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Qin Q, Ding A, Qubie WL, Kumar P, Hu S, Yao T, Zhang J. Microstructure parameter-dependent non-collinear magnetic structures in scandium-doped M-type hexaferrite nanocrystals. NANOSCALE 2024. [PMID: 38976287 DOI: 10.1039/d4nr01642d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
The quest for materials with non-collinear magnetic structures has been driven by their unique properties and potential applications in advanced spintronics and data storage technologies. In this study, we investigate the induction of a non-collinear conical state in BaFe12O19 (M-type) nanocrystal fibers through the substitution of Fe3+ ions with diamagnetic Sc3+ ions. This substitution introduces an additional parameter for tuning the magnetic structure and allows precise control over the substitution amount. We demonstrate that the non-collinear conical state remains stable within a temperature range of 125 K to 325 K and can be finely adjusted by varying the Sc3+ substitution amount. The selective occupancy of Sc3+ ions at the 2a, 4f2, and 2b sites within the M-type ferrite lattice weakens the super-exchange interaction between Fe1, Fe2, and Fe5 ions. This weakening disrupts interactions between different blocks S/R (R*/S*) and stabilizes the conical state. These findings highlight a significant approach to modulating non-collinear magnetic structures in hexagonal ferrites, with implications for both fundamental research and practical applications in the development of novel magnetic materials.
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Affiliation(s)
- Qiankun Qin
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Afei Ding
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
| | - W L Qubie
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Pushpendra Kumar
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Shixin Hu
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Tianyang Yao
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
| | - Junli Zhang
- School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China.
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5
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Hu K, Li Q, Song D, Jia Y, Liang Z, Wang S, Du H, Wen HH, Ge B. Atomic scale disorder and reconstruction in bulk infinite-layer nickelates lacking superconductivity. Nat Commun 2024; 15:5104. [PMID: 38877022 PMCID: PMC11178912 DOI: 10.1038/s41467-024-49533-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 06/07/2024] [Indexed: 06/16/2024] Open
Abstract
The recent discovery of superconductivity in infinite-layer nickelate films has sparked significant interest and expanded the realm of superconductors, in which the infinite-layer structure and proper chemical doping are both of the essence. Nonetheless, the reasons for the absence of superconductivity in bulk infinite-layer nickelates remain puzzling. Herein, we investigate atomic defects and electronic structures in bulk infinite-layer Nd0.8Sr0.2NiO2 using scanning transmission electron microscopy. Our observations reveal the presence of three-dimensional (3D) block-like structural domains resulting from intersecting defect structures, disrupting the continuity within crystal grains, which could be a crucial factor in giving rise to the insulating character and inhibiting the emergence of superconductivity. Moreover, the infinite-layer structure, without complete topotactic reduction, retains interstitial oxygen atoms on the Nd atomic plane in bulk nickelates, possibly further aggravating the local distortions of NiO2 planes and hindering the superconductivity. These findings shed light on the existence of structural and atomic defects in bulk nickelates and provide valuable insights into the influence of proper topotactic reduction and structural orders on superconductivity.
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Affiliation(s)
- Kejun Hu
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Qing Li
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China
| | - Dongsheng Song
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China.
| | - Yingze Jia
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Zhiyao Liang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Shuai Wang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China
| | - Haifeng Du
- Anhui Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory, HFIPS, Anhui, Chinese Academy of Sciences, Hefei, China
| | - Hai-Hu Wen
- Center for Superconducting Physics and Materials, National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing, China.
| | - Binghui Ge
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Anhui Key Laboratory of Magnetic Functional Materials and Devices, Institutes of Physical Science and Information Technology, Anhui University, Hefei, China.
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Wan Z, Chen Z, Shi L, Zheng A, Min J, Shen C, Du B, Guo Y, Gao X, Yin J, Ge H, Niu S, Lu H, Yin K, Wu D, Liu Z, Xia Y. Room-Temperature Growth of Square-Millimeter Single-Crystalline Two-Dimensional Metal Halides on Silicon. ACS NANO 2024; 18:15096-15106. [PMID: 38810232 DOI: 10.1021/acsnano.4c02336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Silicon is the cornerstone of electronics and photonics. In this context, almost all integrated devices derived from two-dimensional (2D) materials stay rooted in silicon technology. However, as the growth substrate, silicon has long been thought to be a hindrance for growing 2D materials through bottom-up methods that require high growth temperatures, and thus, indirect routes are usually considered instead. Although promising growth of large-area 2D materials on silicon has been demonstrated, the direct growth of single-crystalline materials using low-thermal-budget synthesis methods remains challenging. Here, we report the room-temperature growth of millimeter-scale single-crystal 2D metal halides on silicon substrates with a hydroxyl-terminated surface. Theoretical calculations reveal that the activation energy for surface diffusion can be reduced by an order of magnitude by terminating the surface with hydroxyl groups, from which on-silicon growth is greatly facilitated at room temperature and enables a 4-order-of-magnitude increase in area. The high quality and uniformity of the resulting single crystals are further evidenced. The optoelectronic devices employing the as-grown materials show an ultralow dark current of 10-13 A and a high detectivity of 1013 Jones, thereby corroborating a weak-light detection ability. These results would point to a rich space of surface modulation that can be used to surmount current limitations and demonstrate a promising strategy for growing 2D materials directly on silicon at room temperature to produce large single crystals.
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Affiliation(s)
- Zuteng Wan
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zhiwen Chen
- Department of Materials Science and Engineering, University of Toronto, Toronto, Ontario M5S3E4, Canada
| | - Lei Shi
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026, China
| | - Anqi Zheng
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Jin Min
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Cong Shen
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Bingfeng Du
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yanhua Guo
- College of Materials Science and Engineering, Tech Institute for Advanced Materials, Nanjing Tech University, Nanjing 211816, China
| | - Xu Gao
- Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Jiang Yin
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Haixiong Ge
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Shanyuan Niu
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Haiming Lu
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Kuibo Yin
- SEU-FEI Nano-Pico Center, Key Laboratory of MEMS of Ministry of Education, Southeast University, Nanjing 210096, China
| | - Di Wu
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Zhiguo Liu
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
| | - Yidong Xia
- Department of Materials Science and Engineering, College of Engineering and Applied Sciences, Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing 210093, China
- National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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Ong CS, Donzel-Gargand O, Berastegui P, Cedervall J, Bayrak Pehlivan I, Hervoches C, Beran P, Edvinsson T, Eriksson O, Jansson U. The Crystal Structure of Al 4SiC 4 Revisited. Inorg Chem 2024; 63:10490-10499. [PMID: 38801717 PMCID: PMC11167590 DOI: 10.1021/acs.inorgchem.4c00560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 04/21/2024] [Accepted: 05/16/2024] [Indexed: 05/29/2024]
Abstract
Al4SiC4 is a ternary wide-band-gap semiconductor with a high strength-to-weight ratio and excellent oxidation resistance. It consists of slabs of Al4C3 separated by SiC layers with the space group of P63mc. The space group allows Si to occupy two different 2a Wykoff sites, with previous studies reporting that Si occupies only one of the two sites, giving it an ordered structure. Another hitherto unexplored possibility is that Si can be randomly distributed on both 2a sites. In this work, we revisit the published ordered crystal structure using experimental methods and density functional theory (DFT). Al4SiC4 was synthesized by high-temperature sintering at 1800 °C from a powder mixture of Al4C3 and SiC. Neutron diffraction confirmed that Al4SiC4 crystallized with the space group of P63mc, with diffraction patterns that could be fitted to both the ordered and the disordered structures. Scanning transmission electron microscopy, however, provided clear evidence supporting the latter, with DFT calculations further confirming that it is 0.16 eV lower in energy per Al4SiC4 formula unit than the former. TEM analysis revealed Al vacancies in some of the atomic layers that can introduce p-type doping and direct band gaps of 0.7 and 1.2 eV, agreeing with our optical measurements. Finally, we propose that although the calculated formation energy of the Al vacancies is high, the vacancies are stabilized by entropy effects at the high synthesis temperature. This indicates that the cooling procedure after high-temperature synthesis can be important in determining the vacancy content and the electronic properties of Al4SiC4.
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Affiliation(s)
- Chin Shen Ong
- Department
of Physics and Astronomy, Uppsala University, P.O. Box 516, S-75120 Uppsala, Sweden
| | - Olivier Donzel-Gargand
- Division
of Solar Cell Technology, Department of Materials Science and Engineering, Uppsala University, S-75121 Uppsala, Sweden
| | - Pedro Berastegui
- Department
of Chemistry, Ångström Laboratory, Uppsala University, P.O. Box 538, S-75121 Uppsala, Sweden
| | - Johan Cedervall
- Department
of Chemistry, Ångström Laboratory, Uppsala University, P.O. Box 538, S-75121 Uppsala, Sweden
| | - Ilknur Bayrak Pehlivan
- Department
of Materials Science and Engineering, Ångström Laboratory, P.O. Box 35, S-75103 Uppsala, Sweden
| | | | - Premysl Beran
- Nuclear
Physics Institute CAS, Rez 25068, Czech Republic
- European
Spallation Source, ESS ERIC, S-221 00 Lund, Sweden
| | - Tomas Edvinsson
- Department
of Materials Science and Engineering, Ångström Laboratory, P.O. Box 35, S-75103 Uppsala, Sweden
| | - Olle Eriksson
- Department
of Physics and Astronomy, Uppsala University, P.O. Box 516, S-75120 Uppsala, Sweden
- Wallenberg
Initiative Materials Science for Sustainability, Uppsala University, S-75121 Uppsala, Sweden
| | - Ulf Jansson
- Department
of Chemistry, Ångström Laboratory, Uppsala University, P.O. Box 538, S-75121 Uppsala, Sweden
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8
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Voss L, Gaida NA, Hansen AL, Etter M, Wolff N, Duppel V, Lotnyk A, Bensch W, Ebert H, Mankovsky S, Polesya S, Bhat S, Farla R, Hasegawa M, Sasaki T, Niwa K, Kienle L. Synthesis and in-depth structure determination of a novel metastable high-pressure CrTe 3 phase. J Appl Crystallogr 2024; 57:755-769. [PMID: 38846770 PMCID: PMC11151671 DOI: 10.1107/s1600576724002711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 03/25/2024] [Indexed: 06/09/2024] Open
Abstract
This study reports the synthesis and crystal structure determination of a novel CrTe3 phase using various experimental and theoretical methods. The average stoichiometry and local phase separation of this quenched high-pressure phase were characterized by ex situ synchrotron powder X-ray diffraction and total scattering. Several structural models were obtained using simulated annealing, but all suffered from an imperfect Rietveld refinement, especially at higher diffraction angles. Finally, a novel stoichiometrically correct crystal structure model was proposed on the basis of electron diffraction data and refined against powder diffraction data using the Rietveld method. Scanning electron microscopy-energy-dispersive X-ray spectrometry (EDX) measurements verified the targeted 1:3 (Cr:Te) average stoichiometry for the starting compound and for the quenched high-pressure phase within experimental errors. Scanning transmission electron microscopy (STEM)-EDX was used to examine minute variations of the Cr-to-Te ratio at the nanoscale. Precession electron diffraction (PED) experiments were applied for the nanoscale structure analysis of the quenched high-pressure phase. The proposed monoclinic model from PED experiments provided an improved fit to the X-ray patterns, especially after introducing atomic anisotropic displacement parameters and partial occupancy of Cr atoms. Atomic resolution STEM and simulations were conducted to identify variations in the Cr-atom site-occupancy factor. No significant variations were observed experimentally for several zone axes. The magnetic properties of the novel CrTe3 phase were investigated through temperature- and field-dependent magnetization measurements. In order to understand these properties, auxiliary theoretical investigations have been performed by first-principles electronic structure calculations and Monte Carlo simulations. The obtained results allow the observed magnetization behavior to be interpreted as the consequence of competition between the applied magnetic field and the Cr-Cr exchange interactions, leading to a decrease of the magnetization towards T = 0 K typical for antiferromagnetic systems, as well as a field-induced enhanced magnetization around the critical temperature due to the high magnetic susceptibility in this region.
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Affiliation(s)
- Lennart Voss
- Department of Materials Science, Synthesis and Real Structure, Christian-Albrechts-University Kiel, Kaiserstrasse 2, Kiel, 24143, Germany
| | - Nico Alexander Gaida
- Department of Materials Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Anna-Lena Hansen
- Institute for Applied Materials – Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, 76344, Germany
| | - Martin Etter
- Deutsche Elektronen-Synchrotron DESY, Notkestrasse 85, Hamburg, 22607, Germany
| | - Niklas Wolff
- Department of Materials Science, Synthesis and Real Structure, Christian-Albrechts-University Kiel, Kaiserstrasse 2, Kiel, 24143, Germany
- Kiel Nano, Surface and Interface Science KiNSIS, Kiel University, Christian-Albrechts-Platz 4, Kiel, 24118, Germany
| | - Viola Duppel
- Max Planck Institute for Solid State Research, Heisenbergstrasse 1, Stuttgart, 70569, Germany
| | - Andriy Lotnyk
- Leibniz Institute for Surface Modification (IOM), Permoserstrasse 15, Leipzig, 04318, Germany
| | - Wolfgang Bensch
- Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth Strasse 2, Kiel, 24118, Germany
| | - Hubert Ebert
- Department Chemie, Physikalische Chemie, Universität München, Butenandtstrasse 5-13, München, D-81377, Germany
| | - Sergey Mankovsky
- Department Chemie, Physikalische Chemie, Universität München, Butenandtstrasse 5-13, München, D-81377, Germany
| | - Svitlana Polesya
- Department Chemie, Physikalische Chemie, Universität München, Butenandtstrasse 5-13, München, D-81377, Germany
| | - Shrikant Bhat
- Deutsche Elektronen-Synchrotron DESY, Notkestrasse 85, Hamburg, 22607, Germany
| | - Robert Farla
- Deutsche Elektronen-Synchrotron DESY, Notkestrasse 85, Hamburg, 22607, Germany
| | - Masashi Hasegawa
- Department of Materials Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Takuya Sasaki
- Department of Materials Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Ken Niwa
- Department of Materials Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Lorenz Kienle
- Department of Materials Science, Synthesis and Real Structure, Christian-Albrechts-University Kiel, Kaiserstrasse 2, Kiel, 24143, Germany
- Kiel Nano, Surface and Interface Science KiNSIS, Kiel University, Christian-Albrechts-Platz 4, Kiel, 24118, Germany
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9
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Ji S, Wang Y, Hwang J, Chu J, Kim K, Jung HJ, Shin B. Additive-Assisted Hydrothermal Growth Enabling Defect Passivation and Void Remedy in Antimony Selenosulfide Solar Cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2402935. [PMID: 38809078 DOI: 10.1002/smll.202402935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Revised: 05/12/2024] [Indexed: 05/30/2024]
Abstract
Antimony selenosulfide (Sb2(S,Se)3) has recently emerged as a promising light-absorbing material, attributed to its tunable photovoltaic properties, low toxicity, and robust environmental stability. However, despite these advantages, the current record efficiency for Sb2(S,Se)3 solar cells significantly lags behind their Shockley-Queisser limit, especially when compared to other well-established chalcogenide-based thin-film solar cells, such as CdTe and Cu(In,Ga)Se2. This underperformance primarily arises from the formation of unfavorable defects, predominately located at deep energy levels, which act as recombination centers, thereby limiting the potential for performance enhancement in Sb2(S,Se)3 solar cells. Specifically, deep-level defects, such as sulfur vacancy (VS), have a lower formation energy, leading to severe non-radiative recombination and compromising device performance. To address this challenge, thioacetamide (TA), a sulfur-containing additive is introduced, into the precursor solution for the hydrothermal deposition of Sb2(S,Se)3. This results indicate that the incorporation of TA helps in passivating deep-level defects such as sulfur vacancies and in suppressing the formation of large voids within the Sb2(S,Se)3 absorber. Consequently, Sb2(S,Se)3 solar cells, with reduced carrier recombination and improved film quality, achieved a power conversion efficiency of 9.04%, with notable improvements in open-circuit voltage and fill factor. This work provides deeper insights into the passivation of deep-level donor-like VS defects through the incorporation of a sulfur-containing additive, highlighting pathways to enhance the photovoltaic performance of Sb2(S,Se)3 solar cells.
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Affiliation(s)
- Seunghwan Ji
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Yazi Wang
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Jiseon Hwang
- Emerging Material Metrology Group, Division of Chemical and Material Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, South Korea
| | - Jinwoo Chu
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
| | - Kihwan Kim
- Emerging Material Metrology Group, Division of Chemical and Material Metrology, Korea Research Institute of Standards and Science (KRISS), Daejeon, 34113, South Korea
| | - Hee Joon Jung
- Photovoltaics Research Department, Korea Institute of Energy Research, Daejeon, 34129, South Korea
| | - Byungha Shin
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, South Korea
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10
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Zhan Z, Liu Y, Wang W, Du G, Cai S, Wang P. Atomic-level imaging of beam-sensitive COFs and MOFs by low-dose electron microscopy. NANOSCALE HORIZONS 2024; 9:900-933. [PMID: 38512352 DOI: 10.1039/d3nh00494e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Electron microscopy, an important technique that allows for the precise determination of structural information with high spatiotemporal resolution, has become indispensable in unravelling the complex relationships between material structure and properties ranging from mesoscale morphology to atomic arrangement. However, beam-sensitive materials, particularly those comprising organic components such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), would suffer catastrophic damage from the high energy electrons, hindering the determination of atomic structures. A low-dose approach has arisen as a possible solution to this problem based on the integration of advancements in several aspects: electron optical system, detector, image processing, and specimen preservation. This article summarizes the transmission electron microscopy characterization of MOFs and COFs, including local structures, host-guest interactions, and interfaces at the atomic level. Revolutions in advanced direct electron detectors, algorithms in image acquisition and processing, and emerging methodology for high quality low-dose imaging are also reviewed. Finally, perspectives on the future development of electron microscopy methodology with the support of computer science are presented.
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Affiliation(s)
- Zhen Zhan
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong SAR, China.
| | - Yuxin Liu
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong SAR, China.
| | - Weizhen Wang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong SAR, China.
| | - Guangyu Du
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong SAR, China.
| | - Songhua Cai
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon 999077, Hong Kong SAR, China.
| | - Peng Wang
- Department of Physics, University of Warwick, CV4 7AL, Coventry, UK.
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11
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Ma Y, Shi J, Guzman R, Li A, Zhou W. Aberration Correction for Large-Angle Illumination Scanning Transmission Electron Microscopy by Using Iterative Electron Ptychography Algorithms. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2024; 30:226-235. [PMID: 38578297 DOI: 10.1093/mam/ozae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 01/21/2024] [Accepted: 01/24/2024] [Indexed: 04/06/2024]
Abstract
Modern aberration correctors in the scanning transmission electron microscope (STEM) have dramatically improved the attainable spatial resolution and enabled atomical structure and spectroscopic analysis even at low acceleration voltages (≤80 kV). For a large-angle illumination, achieving successful aberration correction to high angles is challenging with an aberration corrector, which limits further improvements in applications such as super-resolution, three-dimensional atomic depth resolution, or atomic surface morphology analyses. Electron ptychography based on four-dimensional STEM can provide a postprocessing strategy to overcome the current technological limitations. In this work, we have demonstrated that aberration correction for large-angle illumination is feasible by pushing the capabilities of regularized ptychographic iterative engine algorithms to reconstruct 4D data sets acquired using a relatively low-efficiency complementary metal oxide semiconductor camera. We report super resolution (0.71 Å) with large-angle illumination (50-60 mrad) and under 60 kV accelerating voltage.
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Affiliation(s)
- Yinhang Ma
- School of Physical Sciences and CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Jinan Shi
- School of Physical Sciences and CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Roger Guzman
- School of Physical Sciences and CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Ang Li
- School of Physical Sciences and CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China
| | - Wu Zhou
- School of Physical Sciences and CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing 100190, China
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12
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Okello ON, Yang DH, Seo SY, Park J, Moon G, Shin D, Chu YS, Yang S, Mizoguchi T, Jo MH, Choi SY. Atomistic Probing of Defect-Engineered 2H-MoTe 2 Monolayers. ACS NANO 2024; 18:6927-6935. [PMID: 38374663 PMCID: PMC10919086 DOI: 10.1021/acsnano.3c08606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 02/01/2024] [Accepted: 02/05/2024] [Indexed: 02/21/2024]
Abstract
Point defects dictate various physical, chemical, and optoelectronic properties of two-dimensional (2D) materials, and therefore, a rudimentary understanding of the formation and spatial distribution of point defects is a key to advancement in 2D material-based nanotechnology. In this work, we performed the demonstration to directly probe the point defects in 2H-MoTe2 monolayers that are tactically exposed to (i) 200 °C-vacuum-annealing and (ii) 532 nm-laser-illumination; and accordingly, we utilize a deep learning algorithm to classify and quantify the generated point defects. We discovered that tellurium-related defects are mainly generated in both 2H-MoTe2 samples; but interestingly, 200 °C-vacuum-annealing and 532 nm-laser-illumination modulate a strong n-type and strong p-type 2H-MoTe2, respectively. While 200 °C-vacuum-annealing generates tellurium vacancies or tellurium adatoms, 532 nm-laser-illumination prompts oxygen atoms to be adsorbed/chemisorbed at tellurium vacancies, giving rise to the p-type characteristic. This work significantly advances the current understanding of point defect engineering in 2H-MoTe2 monolayers and other 2D materials, which is critical for developing nanoscale devices with desired functionality.
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Affiliation(s)
- Odongo
Francis Ngome Okello
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Samsung
Electronics, Foundry Analysis & Engineering Team, Global Manufacturing & Infra Technology, Samsungjeonja-ro 1, Hwaseong-si 18448, Republic
of Korea
| | - Dong-Hwan Yang
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Center
for Van der Waals Quantum Solids, Institute
of Basic Science (IBS), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
| | - Seung-Young Seo
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
| | - Jewook Park
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Center
for Van der Waals Quantum Solids, Institute
of Basic Science (IBS), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
| | - Gunho Moon
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Center
for Van der Waals Quantum Solids, Institute
of Basic Science (IBS), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
| | - Dongwon Shin
- Materials
Science and Technology Division, Oak Ridge
National Laboratory (ORNL), Oak Ridge, Tennessee 37831, United States
| | - Yu-Seong Chu
- Division
of Biomedical Engineering, College of Health Sciences, Yonsei University, 1, Yeonsedae-gil, Heungeop-myeon, Wonju-si 26493, Republic of Korea
| | - Sejung Yang
- Department
of Precision Medicine, Yonsei University,
Wonju College of Medicine, 20 Ilsan-ro, Wonju-si 26426, Republic of Korea
- Department
of Medical Informatics and Biostatistics, Graduate School, Yonsei University, 20 Ilsan-ro, Wonju-si 26426, Republic
of Korea
| | - Teruyasu Mizoguchi
- Institute
of Industrial Science, The University of
Tokyo, Komaba, Meguro 4-6-1, Tokyo 153-8505, Japan
| | - Moon-Ho Jo
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Center
for Van der Waals Quantum Solids, Institute
of Basic Science (IBS), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
| | - Si-Young Choi
- Department
of Materials Science and Engineering, Pohang
University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Center
for Van der Waals Quantum Solids, Institute
of Basic Science (IBS), 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
- Department
of Semiconductor Engineering, POSTECH, 77 Cheongam-ro, Nam-gu, Pohang-si 37673, Republic of Korea
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13
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Duan X, Sha Q, Li P, Li T, Yang G, Liu W, Yu E, Zhou D, Fang J, Chen W, Chen Y, Zheng L, Liao J, Wang Z, Li Y, Yang H, Zhang G, Zhuang Z, Hung SF, Jing C, Luo J, Bai L, Dong J, Xiao H, Liu W, Kuang Y, Liu B, Sun X. Dynamic chloride ion adsorption on single iridium atom boosts seawater oxidation catalysis. Nat Commun 2024; 15:1973. [PMID: 38438342 PMCID: PMC10912682 DOI: 10.1038/s41467-024-46140-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/15/2024] [Indexed: 03/06/2024] Open
Abstract
Seawater electrolysis offers a renewable, scalable, and economic means for green hydrogen production. However, anode corrosion by Cl- pose great challenges for its commercialization. Herein, different from conventional catalysts designed to repel Cl- adsorption, we develop an atomic Ir catalyst on cobalt iron layered double hydroxide (Ir/CoFe-LDH) to tailor Cl- adsorption and modulate the electronic structure of the Ir active center, thereby establishing a unique Ir-OH/Cl coordination for alkaline seawater electrolysis. Operando characterizations and theoretical calculations unveil the pivotal role of this coordination state to lower OER activation energy by a factor of 1.93. The Ir/CoFe-LDH exhibits a remarkable oxygen evolution reaction activity (202 mV overpotential and TOF = 7.46 O2 s-1) in 6 M NaOH+2.8 M NaCl, superior over Cl--free 6 M NaOH electrolyte (236 mV overpotential and TOF = 1.05 O2 s-1), with 100% catalytic selectivity and stability at high current densities (400-800 mA cm-2) for more than 1,000 h.
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Affiliation(s)
- Xinxuan Duan
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore, 637459, Singapore
| | - Qihao Sha
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Pengsong Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, PR China
| | - Tianshui Li
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Guotao Yang
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Wei Liu
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Ende Yu
- Ocean Hydrogen Energy R&D Center, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, PR China
| | - Daojin Zhou
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Jinjie Fang
- State Key Lab of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, 100029, Beijing, PR China
| | - Wenxing Chen
- Energy & Catalysis Center, School of Materials Science & Engineering, Beijing Institute of Technology, Beijing, 100081, PR China
| | - Yizhen Chen
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, 230026, PR China
| | - Lirong Zheng
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, PR China
| | - Jiangwen Liao
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, PR China
| | - Zeyu Wang
- Department of Chemistry, Tsinghua University, 100084, Beijing, PR China
| | - Yaping Li
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Hongbin Yang
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, 999077, PR China
| | - Guoxin Zhang
- College of Energy, Shandong University of Science and Technology, Tsingtao, 266590, PR China
| | - Zhongbin Zhuang
- State Key Lab of Organic-Inorganic Composites, College of Chemical Engineering, Beijing University of Chemical Technology, 100029, Beijing, PR China
- Beijing Key Laboratory of Energy Environmental Catalysis, Beijing University of Chemical Technology, 100029, Beijing, PR China
| | - Sung-Fu Hung
- Department of Applied Chemistry and Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu, 300, Taiwan
| | - Changfei Jing
- School of Materials Science and Engineering, Tianjin Key Lab of Photoelectric Materials & Devices, Tianjin University of Technology, Tianjin, 300384, PR China
| | - Jun Luo
- ShenSi Lab, Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Shenzhen, 518110, PR China
| | - Lu Bai
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, National Center for Nanoscience and Technology, 100190, Beijing, PR China
| | - Juncai Dong
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, 100049, Beijing, PR China
| | - Hai Xiao
- Department of Chemistry, Tsinghua University, 100084, Beijing, PR China
| | - Wen Liu
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China
| | - Yun Kuang
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China.
- Ocean Hydrogen Energy R&D Center, Research Institute of Tsinghua University in Shenzhen, Shenzhen, 518057, PR China.
| | - Bin Liu
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong SAR, 999077, PR China.
- Department of Chemistry & Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong SAR, 999077, PR China.
| | - Xiaoming Sun
- State Key Laboratory of Chemical Resource Engineering, Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, PR China.
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14
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Nguyen KX, Jiang Y, Lee CH, Kharel P, Zhang Y, van der Zande AM, Huang PY. Achieving sub-0.5-angstrom-resolution ptychography in an uncorrected electron microscope. Science 2024; 383:865-870. [PMID: 38386746 DOI: 10.1126/science.adl2029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/19/2024] [Indexed: 02/24/2024]
Abstract
Subangstrom resolution has long been limited to aberration-corrected electron microscopy, where it is a powerful tool for understanding the atomic structure and properties of matter. Here, we demonstrate electron ptychography in an uncorrected scanning transmission electron microscope (STEM) with deep subangstrom spatial resolution down to 0.44 angstroms, exceeding the conventional resolution of aberration-corrected tools and rivaling their highest ptychographic resolutions. Our approach, which we demonstrate on twisted two-dimensional materials in a widely available commercial microscope, far surpasses prior ptychographic resolutions (1 to 5 angstroms) of uncorrected STEMs. We further show how geometric aberrations can create optimized, structured beams for dose-efficient electron ptychography. Our results demonstrate that expensive aberration correctors are no longer required for deep subangstrom resolution.
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Affiliation(s)
- Kayla X Nguyen
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Yi Jiang
- Advanced Photon Source Facility, Argonne National Laboratory, Lemont, IL, USA
| | - Chia-Hao Lee
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Priti Kharel
- Department of Chemistry, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Yue Zhang
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Arend M van der Zande
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, USA
| | - Pinshane Y Huang
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL, USA
- Materials Research Laboratory, University of Illinois Urbana-Champaign, Urbana, IL, USA
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15
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Smith JG, Sawant KJ, Zeng Z, Eldred TB, Wu J, Greeley JP, Gao W. Disproportionation chemistry in K 2PtCl 4 visualized at atomic resolution using scanning transmission electron microscopy. SCIENCE ADVANCES 2024; 10:eadi0175. [PMID: 38335285 PMCID: PMC10857378 DOI: 10.1126/sciadv.adi0175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 01/10/2024] [Indexed: 02/12/2024]
Abstract
The direct observation of a solid-state chemical reaction can reveal otherwise hidden mechanisms that control the reaction kinetics. However, probing the chemical bond breaking and formation at the molecular level remains challenging because of the insufficient spatial-temporal resolution and composition analysis of available characterization methods. Using atomic-resolution differential phase-contrast imaging in scanning transmission electron microscopy, we have visualized the decomposition chemistry of K2PtCl4 to identify its transient intermediate phases and their interfaces that characterize the chemical reduction process. The crystalline structure of K2PtCl4 is found to undergo a disproportionation reaction to form K2PtCl6, followed by gradual reduction to crystalline Pt metal and KCl. By directly imaging different Pt─Cl bond configurations and comparing them to models predicted via density functional theory calculations, a causal connection between the initial and final states of a chemical reaction is established, showcasing new opportunities to resolve reaction pathways through atomistic experimental visualization.
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Affiliation(s)
- Jacob G. Smith
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Kaustubh J. Sawant
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Zhenhua Zeng
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Tim B. Eldred
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Jianbo Wu
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China
- Center of Hydrogen Science, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
| | - Jeffrey P. Greeley
- Davidson School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA
| | - Wenpei Gao
- Future Material Innovation Center, Zhangjiang Institute for Advanced Study, Shanghai Jiao Tong University, Shanghai 200240, P. R. China
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, USA
- State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, P. R. China
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16
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Yang DH, Chu YS, Okello OFN, Seo SY, Moon G, Kim KH, Jo MH, Shin D, Mizoguchi T, Yang S, Choi SY. Full automation of point defect detection in transition metal dichalcogenides through a dual mode deep learning algorithm. MATERIALS HORIZONS 2024; 11:747-757. [PMID: 37990857 DOI: 10.1039/d3mh01500a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
Point defects often appear in two-dimensional (2D) materials and are mostly correlated with physical phenomena. The direct visualisation of point defects, followed by statistical inspection, is the most promising way to harness structure-modulated 2D materials. Here, we introduce a deep learning-based platform to identify the point defects in 2H-MoTe2: synergy of unit cell detection and defect classification. These processes demonstrate that segmenting the detected hexagonal cell into two unit cells elaborately cropped the unit cells: further separating a unit cell input into the Te2/Mo column part remarkably increased the defect classification accuracies. The concentrations of identified point defects were 7.16 × 1020 cm2 of Te monovacancies, 4.38 × 1019 cm2 of Te divacancies and 1.46 × 1019 cm2 of Mo monovacancies generated during an exfoliation process for TEM sample-preparation. These revealed defects correspond to the n-type character mainly originating from Te monovacancies, statistically. Our deep learning-oriented platform combined with atomic structural imaging provides the most intuitive and precise way to analyse point defects and, consequently, insight into the defect-property correlation based on deep learning in 2D materials.
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Affiliation(s)
- Dong-Hwan Yang
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
- Center for van der Waals Quantum Solids, Institute of Basic Science (IBS), 77 Cheongam-Ro, Pohang 37673, Republic of Korea
| | - Yu-Seong Chu
- Division of Biomedical Engineering, College of Health Sciences, Yonsei University, 1, Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do, 26493, Republic of Korea
| | - Odongo Francis Ngome Okello
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
| | - Seung-Young Seo
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
| | - Gunho Moon
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
- Center for van der Waals Quantum Solids, Institute of Basic Science (IBS), 77 Cheongam-Ro, Pohang 37673, Republic of Korea
| | - Kwang Ho Kim
- Department of Materials Science and Engineering, Pusan National University (PNU), 2, Busandaehak-ro 63beon-gil, Geumjeong-gu, 46241, Busan, Republic of Korea
| | - Moon-Ho Jo
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
- Center for van der Waals Quantum Solids, Institute of Basic Science (IBS), 77 Cheongam-Ro, Pohang 37673, Republic of Korea
| | - Dongwon Shin
- Materials Science and Technology Division, Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831, USA
| | - Teruyasu Mizoguchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 15308505, Japan
| | - Sejung Yang
- Department of Precision Medicine, Yonsei University Wonju College of Medicine, 20, Ilsan-ro, Wonju-si, Gangwon-do, Republic of Korea.
| | - Si-Young Choi
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang 37673, Republic of Korea.
- Center for van der Waals Quantum Solids, Institute of Basic Science (IBS), 77 Cheongam-Ro, Pohang 37673, Republic of Korea
- Department of Semiconductor Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Pohang, 37673, Republic of Korea
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17
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Li Z, Zhang H, Li G, Guo J, Wang Q, Deng Y, Hu Y, Hu X, Liu C, Qin M, Shen X, Yu R, Gao X, Liao Z, Liu J, Hou Z, Zhu Y, Fu X. Room-temperature sub-100 nm Néel-type skyrmions in non-stoichiometric van der Waals ferromagnet Fe 3-xGaTe 2 with ultrafast laser writability. Nat Commun 2024; 15:1017. [PMID: 38310096 PMCID: PMC10838308 DOI: 10.1038/s41467-024-45310-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 01/19/2024] [Indexed: 02/05/2024] Open
Abstract
Realizing room-temperature magnetic skyrmions in two-dimensional van der Waals ferromagnets offers unparalleled prospects for future spintronic applications. However, due to the intrinsic spin fluctuations that suppress atomic long-range magnetic order and the inherent inversion crystal symmetry that excludes the presence of the Dzyaloshinskii-Moriya interaction, achieving room-temperature skyrmions in 2D magnets remains a formidable challenge. In this study, we target room-temperature 2D magnet Fe3GaTe2 and unveil that the introduction of iron-deficient into this compound enables spatial inversion symmetry breaking, thus inducing a significant Dzyaloshinskii-Moriya interaction that brings about room-temperature Néel-type skyrmions with unprecedentedly small size. To further enhance the practical applications of this finding, we employ a homemade in-situ optical Lorentz transmission electron microscopy to demonstrate ultrafast writing of skyrmions in Fe3-xGaTe2 using a single femtosecond laser pulse. Our results manifest the Fe3-xGaTe2 as a promising building block for realizing skyrmion-based magneto-optical functionalities.
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Grants
- This work was supported by the National Key Research and Development Program of China at grant No. 2020YFA0309300, Science and Technology Projects in Guangzhou (grant No. 202201000008), the National Natural Science Foundation of China (NSFC) at grant No. 12304146, 11974191, 12127803, 52322108, 52271178, U22A20117 and 12241403, China Postdoctoral Science Foundation (2023M741828), Guangdong Basic and Applied Basic Research Foundation (grant No. 2021B1515120047 and 2023B1515020112), the Natural Science Foundation of Tianjin at grant No. 20JCJQJC00210, the 111 Project at grant No. B23045, and the “Fundamental Research Funds for the Central Universities”, Nankai University (grant No. 63213040, C029211101, C02922101, ZB22000104 and DK2300010207). This work was supported by the Synergetic Extreme Condition User Facility (SECUF).
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Affiliation(s)
- Zefang Li
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Huai Zhang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Guanqi Li
- School of Integrated Circuits, Guangdong University of Technology, Guangzhou, China
| | - Jiangteng Guo
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Qingping Wang
- School of Physics and Electronic and Electrical Engineering, Aba Teachers University, Wenchuan, China
| | - Ying Deng
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Yue Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Xuange Hu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Can Liu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China
| | - Minghui Qin
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Xi Shen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Richeng Yu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
| | - Zhimin Liao
- State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Peking University, Beijing, China
| | - Junming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, China.
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York, USA.
| | - Xuewen Fu
- Ultrafast Electron Microscopy Laboratory, The MOE Key Laboratory of Weak-Light Nonlinear Photonics, School of Physics, Nankai University, Tianjin, China.
- School of Materials Science and Engineering, Smart Sensing Interdisciplinary Science Center, Nankai University, Tianjin, China.
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18
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Yang TY, Gu SW, Zhang YX, Zheng F, Kong D, Dunin-Borkowski RE, Wu D, Ge ZH, Feng J, Jin L. Pseudopolymorphic Phase Engineering for Improved Thermoelectric Performance in Copper Sulfides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2308353. [PMID: 37903494 DOI: 10.1002/adma.202308353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 10/26/2023] [Indexed: 11/01/2023]
Abstract
Polymorphism (and its extended form - pseudopolymorphism) in solids is ubiquitous in mineralogy, crystallography, chemistry/biochemistry, materials science, and the pharmaceutical industries. Despite the difficulty of controlling (pseudo-)polymorphism, the realization of specific (pseudo-)polymorphic phases and associated boundary structures is an efficient route to enhance material performance for energy conversion and electromechanical applications. Here, this work applies the pseudopolymorphic phase (PP) concept to a thermoelectric copper sulfide, Cu2- x S (x ≤ 0.25), via CuBr2 doping. A peak ZT value of 1.25 is obtained at 773 K in Cu1.8 S + 3 wt% CuBr2 , which is 2.3 times higher than that of a pristine Cu1.8 S sample. Atomic-resolution scanning transmission electron microscopy confirms the transformation of pristine Cu1.8 S low digenite into PP-engineered high digenite, as well as the formation of (semi-)coherent interfaces between different PPs, which is expected to enhance phonon scattering. The results demonstrate that PP engineering is an effective approach for achieving improved thermoelectric performance in Cu-S compounds. It is also expected to be useful in other materials.
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Affiliation(s)
- Tian-Yu Yang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Shi-Wei Gu
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Yi-Xin Zhang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Fengshan Zheng
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Electron Microscopy Center, South China University of Technology, Guangzhou, 511442, China
| | - Deli Kong
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Rafal E Dunin-Borkowski
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Di Wu
- Key Laboratory for Macromolecular Science of Shaanxi Province, Shaanxi Key Laboratory for Advanced Energy Devices, School of Materials Science and Engineering, Shaanxi Normal University, Xi'an, 710119, China
| | - Zhen-Hua Ge
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Jing Feng
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Lei Jin
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
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19
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Wong LW, Yang K, Han W, Zheng X, Wong HY, Tsang CS, Lee CS, Lau SP, Ly TH, Yang M, Zhao J. Deciphering the ultra-high plasticity in metal monochalcogenides. NATURE MATERIALS 2024; 23:196-204. [PMID: 38191634 DOI: 10.1038/s41563-023-01788-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 12/11/2023] [Indexed: 01/10/2024]
Abstract
The quest for electronic devices that offer flexibility, wearability, durability and high performance has spotlighted two-dimensional (2D) van der Waals materials as potential next-generation semiconductors. Especially noteworthy is indium selenide, which has demonstrated surprising ultra-high plasticity. To deepen our understanding of this unusual plasticity in 2D van der Waals materials and to explore inorganic plastic semiconductors, we have conducted in-depth experimental and theoretical investigations on metal monochalcogenides (MX) and transition metal dichalcogenides (MX2). We have discovered a general plastic deformation mode in MX, which is facilitated by the synergetic effect of phase transitions, interlayer gliding and micro-cracks. This is in contrast to crystals with strong atomic bonding, such as metals and ceramics, where plasticity is primarily driven by dislocations, twinning or grain boundaries. The enhancement of gliding barriers prevents macroscopic fractures through a pinning effect after changes in stacking order. The discovery of ultra-high plasticity and the phase transition mechanism in 2D MX materials holds significant potential for the design and development of high-performance inorganic plastic semiconductors.
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Affiliation(s)
- Lok Wing Wong
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Ke Yang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Wei Han
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Xiaodong Zheng
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Hok Yin Wong
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Chi Shing Tsang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
| | - Chun-Sing Lee
- Department of Chemistry and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong, China
| | - Shu Ping Lau
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China
| | - Thuc Hue Ly
- Department of Chemistry and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon, Hong Kong, China.
- Department of Chemistry and State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong, China.
- City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
| | - Ming Yang
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
| | - Jiong Zhao
- Department of Applied Physics, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
- The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China.
- The Research Institute for Advanced Manufacturing, The Hong Kong Polytechnic University, Kowloon, Hong Kong, China.
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20
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Buffat PA, Alexandrou I, Czyrska-Filemonowicz A. Composition and Element Distribution Mapping of γ' and γ″ Phases of Inconel 718 by High-Resolution Scanning Transmission Electron Microscopy and X-ray Energy-Dispersive Spectrometry. MATERIALS (BASEL, SWITZERLAND) 2024; 17:594. [PMID: 38591481 PMCID: PMC10856184 DOI: 10.3390/ma17030594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 04/10/2024]
Abstract
The main strengthening mechanism for Inconel 718 (IN718), a Ni-based superalloy, is precipitation hardening by γ' and γ″ particles. It is thus essential, for good alloy performance, that precipitates with the desired chemical composition have adequate size and dispersion. The distribution of the γ' and γ″ phases and their chemical composition were investigated in the nickel-based Inconel 718 superalloy by taking advantage of the new capabilities of scanning transmission electron microscopy and energy-dispersive X-ray spectrometry using a windowless multiple detector, a high-brightness Schottky electron gun, and a spherical aberration corrector in the illumination probe optics. A small routine was developed to deconvolute the respective compositions of γ' and γ″ nanoprecipitates embedded in the γ matrix. Keeping the electron probe current low enough-a few hundred pA-prevented excessive irradiation damage during the acquisition of element maps and brought their spatial resolution down to the atomic column level to track their element compositions. The present results agree with and complement atomic probe tomography observations and Thermo-Calc predictions from the literature. The presence of an Al enrichment at the γ'/γ″ interface-which may control the γ″ phase coarsening-is observed in the last row of Al-Nb-Ti columns along this interface. In addition, a few columns with similar composition changes are found randomly distributed in the γ' phase.
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Affiliation(s)
- Philippe A. Buffat
- Ecole Polytechnique Fédérale de Lausanne, Centre Interdisciplinaire de Microscopie Electronique, Ch. des Vioz 14, 1865 Les Diablerets, Switzerland
| | - Ioannis Alexandrou
- Thermo Fisher Scientific, De Schakel 2, 5651 GH Eindhoven, The Netherlands;
| | - Aleksandra Czyrska-Filemonowicz
- Faculty of Metals Engineering and Computer Science, Centre of Electron Microscopy for Materials Science, AGH University of Science and Technology, al. A. Mickiewicza 30, 30-059 Krakow, Poland;
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21
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Cui Y, Wang J, Li Y, Wu Y, Been E, Zhang Z, Zhou J, Zhang W, Hwang HY, Sinclair R, Cui Y. Twisted epitaxy of gold nanodisks grown between twisted substrate layers of molybdenum disulfide. Science 2024; 383:212-219. [PMID: 38207038 DOI: 10.1126/science.adk5947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/27/2023] [Indexed: 01/13/2024]
Abstract
We expand the concept of epitaxy to a regime of "twisted epitaxy" with the epilayer crystal orientation between two substrates influenced by their relative orientation. We annealed nanometer-thick gold (Au) nanoparticles between two substrates of exfoliated hexagonal molybdenum disulfide (MoS2) with varying orientation of their basal planes with a mutual twist angle ranging from 0° to 60°. Transmission electron microscopy studies show that Au aligns midway between the top and bottom MoS2 when the twist angle of the bilayer is small (<~7°). For larger twist angles, Au has only a small misorientation with the bottom MoS2 that varies approximately sinusoidally with twist angle of the bilayer MoS2. Four-dimensional scanning transmission electron microscopy analysis further reveals a periodic strain variation (<|±0.5%|) in the Au nanodisks associated with the twisted epitaxy, consistent with the Moiré registry of the two MoS2 twisted layers.
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Affiliation(s)
- Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Jingyang Wang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94305, USA
| | - Yanbin Li
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yecun Wu
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Emily Been
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Zewen Zhang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Jiawei Zhou
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Wenbo Zhang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Harold Y Hwang
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Robert Sinclair
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
| | - Yi Cui
- Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
- Department of Energy Science and Engineering, Stanford University, Stanford, CA 94305, USA
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22
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Wei XK, Jalil AR, Rüßmann P, Ando Y, Grützmacher D, Blügel S, Mayer J. Atomic Diffusion-Induced Polarization and Superconductivity in Topological Insulator-Based Heterostructures. ACS NANO 2024; 18:571-580. [PMID: 38126781 PMCID: PMC10786152 DOI: 10.1021/acsnano.3c08601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
The proximity effect at a highly transparent interface of an s-wave superconductor (S) and a topological insulator (TI) provides a promising platform to create Majorana zero modes in artificially designed heterostructures. However, structural and chemical issues pertinent to such interfaces have been poorly explored so far. Here, we report the discovery of Pd diffusion-induced polarization at interfaces between superconductive Pd1+x(Bi0.4Te0.6)2 (xPBT, 0 ≤ x ≤ 1) and Pd-intercalated Bi2Te3 by using atomic-resolution scanning transmission electron microscopy. Our quantitative image analysis reveals that nanoscale lattice strain and QL polarity synergistically suppress and promote Pd diffusion at the normal and parallel interfaces, formed between Te-Pd-Bi triple layers (TLs) and Te-Bi-Te-Bi-Te quintuple layers (QLs), respectively. Further, our first-principles calculations unveil that the superconductivity of the xPBT phase and topological nature of the Pd-intercalated Bi2Te3 phase are robust against the broken inversion symmetry. These findings point out the necessity of considering the coexistence of electric polarization with superconductivity and topology in such S-TI systems.
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Affiliation(s)
- Xian-Kui Wei
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Abdur Rehman Jalil
- Peter
Grünberg Institute and JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Philipp Rüßmann
- Institute
for Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich GmbH and JARA, 52425 Jülich, Germany
| | - Yoichi Ando
- Physics
Institute II, University of Cologne, Zülpicher Straße 77, 50937 Köln, Germany
| | - Detlev Grützmacher
- Peter
Grünberg Institute and JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stefan Blügel
- Peter
Grünberg Institute and Institute for Advanced Simulation, Forschungszentrum Jülich GmbH and JARA, 52425 Jülich, Germany
| | - Joachim Mayer
- Ernst
Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Central
Facility for Electron Microscopy, RWTH Aachen
University, Ahornstraße
55, 52074 Aachen, Germany
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23
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Eliasson H, Niu Y, Palmer RE, Grönbeck H, Erni R. Support-facet-dependent morphology of small Pt particles on ceria. NANOSCALE 2023; 15:19091-19098. [PMID: 37929917 DOI: 10.1039/d3nr04701f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2023]
Abstract
Direct atomic scale information on how the structure of supported nanoparticles is affected by the metal-support interaction is rare. Using scanning transmission electron microscopy, we provide direct evidence of a facet-dependent support interaction for Pt nanoparticles on CeO2, governing the dimensionality of small platinum particles. Our findings indicate that particles consisting of less than ∼130 atoms prefer a 3D shape on CeO2(111) facets, while 2D raft structures are favored on CeO2(100) facets. Measurements of stationary particles on both surface facets are supplemented by time resolved measurements following a single particle with atomic resolution as it migrates from CeO2(111) to CeO2(100), undergoing a dimensionality change from 3D to 2D. The intricate transformation mechanism reveals how the 3D particle disassembles and completely wets a neighboring CeO2(100) facet. Density functional theory calculations confirm the structure-trend and reveal the thermodynamic driving force for the migration of small particles. Knowledge of the presented metal-support interactions is crucial to establish structure-function relationships in a range of applications based on supported nanostructures.
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Affiliation(s)
- Henrik Eliasson
- Electron Microscopy Center, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
| | - Yubiao Niu
- Nanomaterials Lab, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, SA1 8EN, UK
| | - Richard E Palmer
- Nanomaterials Lab, Faculty of Science and Engineering, Swansea University, Bay Campus, Swansea, SA1 8EN, UK
| | - Henrik Grönbeck
- Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-41296 Göteborg, Sweden
| | - Rolf Erni
- Electron Microscopy Center, Empa - Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, 8600 Dübendorf, Switzerland.
- Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
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24
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Nelli D, Roncaglia C, Ferrando R, Kataya Z, Garreau Y, Coati A, Andreazza-Vignolle C, Andreazza P. Sudden collective atomic rearrangements trigger the growth of defect-free silver icosahedra. NANOSCALE 2023; 15:18891-18900. [PMID: 37975176 DOI: 10.1039/d3nr04530g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The growth of Ag clusters on amorphous carbon substrates is studied in situ by X-ray scattering experiments, whose final outcome is imaged by electron microscopy. The real-time analysis of the growth process at room temperature shows the formation of a large majority of icosahedral structures by a shell-by-shell growth mode which produces smooth and nearly defect-free structures. Molecular dynamics simulations supported by ab initio calculations reveal that the shell-by-shell mode is possible because of the occurrence of collective displacements which involve the concerted motion of many atoms of the growing shell. These collective processes are a kind of black swan event, as they occur suddenly and rarely, but their occurrence is decisive for the final outcome of the growth. Annealing and ageing experiments show that the as-grown icosahedra are metastable, in agreement with the energetic stability calculations.
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Affiliation(s)
- Diana Nelli
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy.
| | - Cesare Roncaglia
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy.
| | - Riccardo Ferrando
- Dipartimento di Fisica, Università di Genova, Via Dodecaneso 33, 16146 Genova, Italy.
| | - Zeinab Kataya
- Université d'Orléans, CNRS, ICMN UMR7374, 1b rue de la Férollerie, F-45071 Orléans, France.
| | - Yves Garreau
- Synchrotron Soleil, L'Orme de Merisiers, F-91192 Gif-sur-Yvette, France
- Université de Paris, CNRS, Laboratoire Matériaux et Phénomènes Quantiques UMR7162, F-75013 Paris, France
| | - Alessandro Coati
- Synchrotron Soleil, L'Orme de Merisiers, F-91192 Gif-sur-Yvette, France
| | | | - Pascal Andreazza
- Université d'Orléans, CNRS, ICMN UMR7374, 1b rue de la Férollerie, F-45071 Orléans, France.
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25
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San X, Hu J, Chen M, Niu H, Smeets PJM, Malliakas CD, Deng J, Koo K, Dos Reis R, Dravid VP, Hu X. Unlocking the mysterious polytypic features within vaterite CaCO 3. Nat Commun 2023; 14:7858. [PMID: 38030637 PMCID: PMC10687017 DOI: 10.1038/s41467-023-43625-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/15/2023] [Indexed: 12/01/2023] Open
Abstract
Calcium carbonate (CaCO3), the most abundant biogenic mineral on earth, plays a crucial role in various fields such as hydrosphere, biosphere, and climate regulation. Of the four polymorphs, calcite, aragonite, vaterite, and amorphous CaCO3, vaterite is the most enigmatic one due to an ongoing debate regarding its structure that has persisted for nearly a century. In this work, based on systematic transmission electron microscopy characterizations, crystallographic analysis and machine learning aided molecular dynamics simulations with ab initio accuracy, we reveal that vaterite can be regarded as a polytypic structure. The basic phase has a monoclinic lattice possessing pseudohexagonal symmetry. Direct imaging and atomic-scale simulations provide evidence that a single grain of vaterite can contain three orientation variants. Additionally, we find that vaterite undergoes a second-order phase transition with a critical point of ~190 K. These atomic scale insights provide a comprehensive understanding of the structure of vaterite and offer advanced perspectives on the biomineralization process of calcium carbonate.
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Affiliation(s)
- Xingyuan San
- Hebei Key Lab of Optic-electronic Information and Materials, The College of Physics Science and Technology, Hebei University, Baoding, 071002, China
| | - Junwei Hu
- State Key Laboratory of Solidification Processing, International Center for Materials Discovery, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Mingyi Chen
- State Key Laboratory of Solidification Processing, International Center for Materials Discovery, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Haiyang Niu
- State Key Laboratory of Solidification Processing, International Center for Materials Discovery, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Paul J M Smeets
- Department of Materials Science and Engineering, The NUANCE Center, Northwestern University, Evanston, IL, 60208, USA
| | | | - Jie Deng
- Department of Geosciences, Princeton University, Princeton, NJ, 08544, USA
| | - Kunmo Koo
- Department of Materials Science and Engineering, The NUANCE Center, Northwestern University, Evanston, IL, 60208, USA
| | - Roberto Dos Reis
- Department of Materials Science and Engineering, The NUANCE Center, Northwestern University, Evanston, IL, 60208, USA
| | - Vinayak P Dravid
- Department of Materials Science and Engineering, The NUANCE Center, Northwestern University, Evanston, IL, 60208, USA.
| | - Xiaobing Hu
- Department of Materials Science and Engineering, The NUANCE Center, Northwestern University, Evanston, IL, 60208, USA.
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26
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Xu J, Xue XX, Shao G, Jing C, Dai S, He K, Jia P, Wang S, Yuan Y, Luo J, Lu J. Atomic-level polarization in electric fields of defects for electrocatalysis. Nat Commun 2023; 14:7849. [PMID: 38030621 PMCID: PMC10686988 DOI: 10.1038/s41467-023-43689-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 11/16/2023] [Indexed: 12/01/2023] Open
Abstract
The thriving field of atomic defect engineering towards advanced electrocatalysis relies on the critical role of electric field polarization at the atomic scale. While this is proposed theoretically, the spatial configuration, orientation, and correlation with specific catalytic properties of materials are yet to be understood. Here, by targeting monolayer MoS2 rich in atomic defects, we pioneer the direct visualization of electric field polarization of such atomic defects by combining advanced electron microscopy with differential phase contrast technology. It is revealed that the asymmetric charge distribution caused by the polarization facilitates the adsorption of H*, which originally activates the atomic defect sites for catalytic hydrogen evolution reaction (HER). Then, it has been experimentally proven that atomic-level polarization in electric fields can enhance catalytic HER activity. This work bridges the long-existing gap between the atomic defects and advanced electrocatalysis by directly revealing the angstrom-scale electric field polarization and correlating it with the as-tuned catalytic properties of materials; the methodology proposed here could also inspire future studies focusing on catalytic mechanism understanding and structure-property-performance relationship.
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Affiliation(s)
- Jie Xu
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, China
| | - Xiong-Xiong Xue
- School of Physics and Optoelectronics, Xiangtan University, Xiangtan, 411105, China
| | - Gonglei Shao
- Interdisciplinary Research Center for Sustainable Energy Science and Engineering (IRC4SE2), School of Chemical Engineering, Zhengzhou University, Zhengzhou, 450001, China.
| | - Changfei Jing
- Feringa Nobel Prize Scientist Joint Research Centre, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China
| | - Sheng Dai
- Feringa Nobel Prize Scientist Joint Research Centre, School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China
| | - Kun He
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, China
| | - Peipei Jia
- ShenSi Lab, Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Longhua District, Shenzhen, 518110, China
| | - Shun Wang
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, China
| | - Yifei Yuan
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, China.
| | - Jun Luo
- ShenSi Lab, Shenzhen Institute for Advanced Study, University of Electronic Science and Technology of China, Longhua District, Shenzhen, 518110, China.
| | - Jun Lu
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China.
- Quzhou Institute of Power Battery and Grid Energy Storage, Quzhou, Zhejiang, 324000, China.
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27
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Xu K, Hung SW, Si W, Wu Y, Huo C, Yu P, Zhong X, Zhu J. Topotactically transformable antiphase boundaries with enhanced ionic conductivity. Nat Commun 2023; 14:7382. [PMID: 37968326 PMCID: PMC10651924 DOI: 10.1038/s41467-023-43086-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/30/2023] [Indexed: 11/17/2023] Open
Abstract
Engineering lattice defects have emerged as a promising approach to effectively modulate the functionality of devices. Particularly, antiphase boundaries (APBs) as planar defects have been considered major obstacles to optimizing the ionic conductivity of mixed ionic-electronic conductors (MIECs) in solid oxide fuel applications. Here our study identifies topotactically transformable APBs (tt-APBs) at the atomic level and demonstrates that they exhibit higher ionic conductivity at elevated temperatures as compared to perfect domains. In-situ observation at the atomic scale tracks dynamic oxygen migration across these tt-APBs, where the abundant interstitial sites between tetrahedrons facilitate the ionic migration. Furthermore, annealing in an oxidized atmosphere can lead to the formation of interstitial oxygen at these APBs. These pieces of evidence clearly clarify that the tt-APBs can contribute to oxygen conductivity as anion diffusion channels, while the topotactically non-transformable APBs cannot. The topotactic transformability opens the way of defect engineering strategies for improving ionic transportation in MIECs.
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Grants
- X.Y. Z is grateful for the financial supports from National Natural Science Foundation of China (52171014, 52011530124, 52025024), Science, Technology and Innovation Commission of Shenzhen Municipality (SGDX20210823104200001, JCYJ20210324134402007, HZQB-KCZYB-2020031), the Sino-German Mobility Programme by the Sino-German Center for Research Promotion (M-0265), Innovation and Technology Fund (ITS/365/21), Science and Technology Department of Sichuan Province (2021YFSY0016), the Research Grants Council of Hong Kong Special Administrative Region, China (Project No. E-CityU101/20, 11302121, 11309822, G-CityU102/20), the European Research Council (Grant No. 856538, project “3D MAGiC”), CityU Strategic Interdisciplinary Research Grant (7020016, 7020043), the City University of Hong Kong (Projects no. 9610484, 9680291, 9678288, 9610607), the City University of Hong Kong Shenzhen Research Institute and City University of Hong Kong Chengdu Research Institute.
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Affiliation(s)
- Kun Xu
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, PR China.
- Department of Mechanical Engineering, Stanford University, Palo Alto, 94305, USA.
| | - Shih-Wei Hung
- TRACE EM Unit and Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, 999077, Hong Kong SAR, PR China
- City University of Hong Kong Matter Science Research Institute (Futian, Shenzhen), Shenzhen, 518048, PR China
| | - Wenlong Si
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, PR China
- Ji Hua Laboratory, Foshang, Guangdong, 0757, PR China
| | - Yongshun Wu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, PR China
| | - Chuanrui Huo
- Beijing Advanced Innovation Center for Materials Genome Engineering, Department of Physical Chemistry, University of Science and Technology Beijing, Beijing, 100083, PR China
| | - Pu Yu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, PR China
| | - Xiaoyan Zhong
- TRACE EM Unit and Department of Materials Science and Engineering, City University of Hong Kong, Kowloon, 999077, Hong Kong SAR, PR China.
- City University of Hong Kong Matter Science Research Institute (Futian, Shenzhen), Shenzhen, 518048, PR China.
- Nanomanufacturing Laboratory (NML), Shenzhen Research Institute, City University of Hong Kong, Shenzhen, 518057, PR China.
- Chengdu Research Institute, City University of Hong Kong, Chengdu, 610200, PR China.
| | - Jing Zhu
- National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, PR China.
- Ji Hua Laboratory, Foshang, Guangdong, 0757, PR China.
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28
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Lu Y, Zhou Y, Wang W, Hu M, Huang X, Mao D, Huang S, Xie L, Lin P, Jiang B, Zhu B, Feng J, Shi J, Lou Q, Huang Y, Yang J, Li J, Li G, He J. Staggered-layer-boosted flexible Bi 2Te 3 films with high thermoelectric performance. NATURE NANOTECHNOLOGY 2023; 18:1281-1288. [PMID: 37500776 DOI: 10.1038/s41565-023-01457-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/17/2023] [Indexed: 07/29/2023]
Abstract
Room-temperature bismuth telluride (Bi2Te3) thermoelectrics are promising candidates for low-grade heat harvesting. However, the brittleness and inflexibility of Bi2Te3 are far reaching and bring about lifelong drawbacks. Here we demonstrate good pliability over 1,000 bending cycles and high power factors of 4.2 (p type) and 4.6 (n type) mW m-1 K-2 in Bi2Te3-based films that were exfoliated from corresponding single crystals. This unprecedented bendability was ascribed to the in situ observed staggered-layer structure that was spontaneously formed during the fabrication to promote stress propagation whilst maintaining good electrical conductivity. Unexpectedly, the donor-like staggered layer rarely affected the carrier transport of the films, thus maintaining its superior thermoelectric performance. Our flexible generator showed a high normalized power density of 321 W m-2 with a temperature difference of 60 K. These high performances in supple thermoelectric films not only offer useful paradigms for wearable electronics, but also provide key insights into structure-property manipulation in inorganic semiconductors.
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Affiliation(s)
- Yao Lu
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
- International School of Microelectronics, Dongguan University of Technology, Dongguan, China
| | - Yi Zhou
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Wu Wang
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Mingyuan Hu
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Xiege Huang
- Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology, Wuhan, China
| | - Dasha Mao
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Shan Huang
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Lin Xie
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Peijian Lin
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Binbin Jiang
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Bin Zhu
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Jianghe Feng
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Jianxu Shi
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Qing Lou
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Yi Huang
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Jianmin Yang
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Jinhong Li
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China
| | - Guodong Li
- Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics, Wuhan University of Technology, Wuhan, China
| | - Jiaqing He
- Shenzhen Key Laboratory of Thermoelectric Materials, Department of Physics, Southern University of Science and Technology, Shenzhen, China.
- Guangdong-Hong Kong-Macao Joint Laboratory for Photonic-Thermal-Electrical Energy Materials and Devices, Southern University of Science and Technology, Shenzhen, China.
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29
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Lindner J, Ross U, Meyer T, Boureau V, Seibt M, Jooss C. Reconstruction of Angstrom resolution exit-waves by the application of drift-corrected phase-shifting off-axis electron holography. Ultramicroscopy 2023; 256:113880. [PMID: 37952372 DOI: 10.1016/j.ultramic.2023.113880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 10/05/2023] [Accepted: 10/21/2023] [Indexed: 11/14/2023]
Abstract
Phase-shifting electron holography is an excellent method to reveal electron wave phase information with very high phase sensitivity over a large range of spatial frequencies. It circumvents the limiting trade-off between fringe spacing and visibility of standard off-axis holography. Previous implementations have been limited by the independent drift of biprism and sample. We demonstrate here an advanced drift correction scheme for the hologram series that exploits the presence of an interface of the TEM specimen to the vacuum area in the hologram. It allows to obtain reliable phase information up to 2π/452 at the 1 Å information limit of the Titan 80-300 kV environmental transmission electron microscope used, by applying a moderate voltage of 250 V to a single biprism for a fringe spacing of 1 Å. The obtained phase and amplitude information is validated at a thin Pt sample by use of multislice image simulation with the frozen lattice approximation and shows excellent agreement. The presented method is applicable in any TEM equipped with at least one electron biprism and thus enables achieving high resolution off-axis holography in various instruments including those for in-situ applications. A software implementation for the acquisition, calibration and reconstruction is provided.
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Affiliation(s)
- J Lindner
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Goettingen, Germany
| | - U Ross
- 4th Institute of Physics - Solids and Nanostructures, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Goettingen, Germany
| | - T Meyer
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Goettingen, Germany
| | - V Boureau
- Interdisciplinary Center for Electron Microscopy, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland
| | - M Seibt
- 4th Institute of Physics - Solids and Nanostructures, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Goettingen, Germany
| | - Ch Jooss
- Institute of Materials Physics, University of Goettingen, Friedrich-Hund-Platz 1, 37077, Goettingen, Germany; International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, D-37077, Goettingen, Germany.
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30
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Berlin J, Stegmüller T, Haider F. Observation of in-plane oriented Guinier-Preston zones in Al-Cu. Micron 2023; 173:103504. [PMID: 37517275 DOI: 10.1016/j.micron.2023.103504] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 08/01/2023]
Abstract
Known for a long time, the first metastable precipitate which forms in Al-Cu alloys during natural ageing are the so-called Guinier-Preston zones (GPZ), platelets of Cu on {100} planes of only one atomic layer thickness. Only with the development of aberration corrected transmission electron microscopes (TEM), direct observation and imaging of these platelets was possible, but with the restriction, that only edge view was possible. Here we show that under appropriate conditions an observation in a plan-view is possible and allows further insight into the shape and arrangement of the GP-zones. Furthermore, this demonstrates that single atom detection of one Cu atom in a column of Al atoms is possible.
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Affiliation(s)
- Johannes Berlin
- Institut für Physik, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany.
| | - Tobias Stegmüller
- Institut für Physik, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
| | - Ferdinand Haider
- Institut für Physik, Universität Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany
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31
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Silinga A, Allen CS, Barthel J, Ophus C, MacLaren I. Measurement of Atomic Modulation Direction Using the Azimuthal Variation of First-Order Laue Zone Electron Diffraction. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1682-1687. [PMID: 37639214 DOI: 10.1093/micmic/ozad089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/12/2023] [Accepted: 08/02/2023] [Indexed: 08/29/2023]
Abstract
We show that diffraction intensity into the first-order Laue zone (FOLZ) of a crystal can have a strong azimuthal dependence, where this FOLZ ring appears solely because of unidirectional atom position modulation. Such a modulation was already known to cause the appearance of elliptical columns in atom-resolution images, but we show that measurement of the angle via four-dimensional scanning transmission electron microscopy (4DSTEM) is far more reliable and allows the measurement of the modulation direction with a precision of about 1° and an accuracy of about 3°. This method could be very powerful in characterizing atomic structures in three dimensions by 4DSTEM, especially in cases where the structure is found only in nanoscale regions or crystals.
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Affiliation(s)
- Aurys Silinga
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
| | - Christopher S Allen
- Electron Physical Science Imaging Centre, Diamond Light Source Ltd., Oxford OX11 0DE, UK
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
| | - Juri Barthel
- Ernst Ruska-Centre (ER-C 2), Forschungszentrum Jülich GmbH, Jülich 52425, Germany
| | - Colin Ophus
- NCEM, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ian MacLaren
- SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK
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32
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Kim NY, Cao S, More KL, Lupini AR, Miao J, Chi M. Hollow Ptychography: Toward Simultaneous 4D Scanning Transmission Electron Microscopy and Electron Energy Loss Spectroscopy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2208162. [PMID: 37203310 DOI: 10.1002/smll.202208162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 04/13/2023] [Indexed: 05/20/2023]
Abstract
With the recent development of high-acquisition-speed pixelated detectors, 4D scanning transmission electron microscopy (4D-STEM) is becoming routinely available in high-resolution electron microscopy. 4D-STEM acts as a "universal" method that provides local information on materials that is challenging to extract from bulk techniques. It extends conventional STEM imaging to include super-resolution techniques and to provide quantitative phase-based information, such as differential phase contrast, ptychography, or Bloch wave phase retrieval. However, an important missing factor is the chemical and bonding information provided by electron energy loss spectroscopy (EELS). 4D-STEM and EELS cannot currently be acquired simultaneously due to the overlapping geometry of the detectors. Here, the feasibility of modifying the detector geometry to overcome this challenge for bulk specimens is demonstrated, and the use of a partial or defective detector for ptycholgaphic structural imaging is explored. Results show that structural information beyond the diffraction-limit and chemical information from the material can be extracted together, resulting in simultaneous multi-modal measurements, adding the additional dimensions of spectral information to 4D datasets.
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Affiliation(s)
- Na Yeon Kim
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Shaohong Cao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Karren L More
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Andrew R Lupini
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Jianwei Miao
- Department of Physics and Astronomy and California NanoSystems Institute, University of California, Los Angeles, CA, 90095, USA
| | - Miaofang Chi
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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33
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Liu C, Jiang J, Zhang C, Wang Q, Zhang H, Zheng D, Li Y, Ma Y, Algaidi H, Gao X, Hou Z, Mi W, Liu J, Qiu Z, Zhang X. Controllable Skyrmionic Phase Transition between Néel Skyrmions and Bloch Skyrmionic Bubbles in van der Waals Ferromagnet Fe 3-δ GeTe 2. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303443. [PMID: 37505392 PMCID: PMC10520623 DOI: 10.1002/advs.202303443] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 07/05/2023] [Indexed: 07/29/2023]
Abstract
The van der Waals (vdW) ferromagnet Fe3-δ GeTe2 has garnered significant research interest as a platform for skyrmionic spin configurations, that is, skyrmions and skyrmionic bubbles. However, despite extensive efforts, the origin of the Dzyaloshinskii-Moriya interaction (DMI) in Fe3-δ GeTe2 remains elusive, making it challenging to acquire these skyrmionic phases in a controlled manner. In this study, it is demonstrated that the Fe content in Fe3-δ GeTe2 has a profound effect on the crystal structure, DMI, and skyrmionic phase. For the first time, a marked increase in Fe atom displacement with decreasing Fe content is observed, transforming the original centrosymmetric crystal structure into a non-centrosymmetric symmetry, leading to a considerable DMI. Additionally, by varying the Fe content and sample thickness, a controllable transition between Néel-type skyrmions and Bloch-type skyrmionic bubbles is achieved, governed by a delicate interplay between dipole-dipole interaction and the DMI. The findings offer novel insights into the variable skyrmionic phases in Fe3-δ GeTe2 and provide the impetus for developing vdW ferromagnet-based spintronic devices.
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Affiliation(s)
- Chen Liu
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Jiawei Jiang
- Tianjin Key Laboratory of Low‐Dimensional Materials Physics and Preparation Technology, School of ScienceTianjin UniversityTianjin300354China
| | - Chenhui Zhang
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Qingping Wang
- College of Electronic Information and AutomationAba Teachers UniversityPixian StreetSichuan623002China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China
| | - Huai Zhang
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China
| | - Dongxing Zheng
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Yan Li
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Yinchang Ma
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Hanin Algaidi
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
| | - Xingsen Gao
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China
| | - Zhipeng Hou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China
| | - Wenbo Mi
- Tianjin Key Laboratory of Low‐Dimensional Materials Physics and Preparation Technology, School of ScienceTianjin UniversityTianjin300354China
| | - Jun‐ming Liu
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology & Institute for Advanced MaterialsSouth China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing211102China
| | - Ziqiang Qiu
- Department of PhysicsUniversity of California at BerkeleyBerkeleyCA94720USA
| | - Xixiang Zhang
- Physical Science and Engineering Division (PSE)King Abdullah University of Science and Technology (KAUST)Thuwal23955‐6900Saudi Arabia
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34
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Blin T, Girard A, Fossard F, Guillou N, Catala L, Loiseau A, Huc V. η-Carbides (Co, Mo, or W) Nanoparticles from Octacyanometalates Precursors-Based Network. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2301299. [PMID: 37154245 DOI: 10.1002/smll.202301299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/26/2023] [Indexed: 05/10/2023]
Abstract
This paper describes a simple, two-steps chemical pathway to obtain bimetallic carbide nanoparticles (NPs) of general formula MxM″yC, also called η-carbides. This process allows for a control of the chemical composition of metals present in the carbides (M = Co and M″ = Mo or W). The first step involves the synthesis of a precursor consisting of a network of octacyanometalates. The second step consists in a thermal degradation of the previously obtained octacyanometalates networks under neutral atmosphere (Ar or N2 ). It is shown that this process results in the formation of carbide NPs with diameter of ≈ 5nm, and the stoichiometries Co3 M'3 C, Co6 M'6 C, Co2 M'4 C for the CsCoM' systems.
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Affiliation(s)
- Thomas Blin
- Université Paris Saclay, UMR 104 ONERA-CNRS, LEM, F-92322, Châtillon, 92320, France
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris-Saclay, Orsay, 91190, France
| | - Armelle Girard
- Université Paris Saclay, UMR 104 ONERA-CNRS, LEM, F-92322, Châtillon, 92320, France
- Université de Versailles-Saint-Quentin-En-Yvelines (UVSQ), Université Paris-Saclay, Versailles, 78000, France
| | - Frédéric Fossard
- Université Paris Saclay, UMR 104 ONERA-CNRS, LEM, F-92322, Châtillon, 92320, France
| | - Nathalie Guillou
- Institut Lavoisier de Versailles (ILV), UMR CNRS 8180, UVSQ, Université Paris-Saclay, Versailles, 78000, France
| | - Laure Catala
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris-Saclay, Orsay, 91190, France
| | - Annick Loiseau
- Université Paris Saclay, UMR 104 ONERA-CNRS, LEM, F-92322, Châtillon, 92320, France
| | - Vincent Huc
- Institut de Chimie Moléculaire et des Matériaux d'Orsay (ICMMO), CNRS, Université Paris-Saclay, Orsay, 91190, France
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35
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Mangan GL, Moldovan G, Stewart A. InFluence: An Open-Source Python Package to Model Images Captured with Direct Electron Detectors. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1380-1401. [PMID: 37488831 DOI: 10.1093/micmic/ozad064] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 04/26/2023] [Accepted: 05/03/2023] [Indexed: 07/26/2023]
Abstract
The high detection efficiencies of direct electron detectors facilitate the routine collection of low fluence electron micrographs and diffraction patterns. Low dose and low fluence electron microscopy experiments are the only practical way to acquire useful data from beam sensitive pharmaceutical and biological materials. Appropriate modeling of low fluence images acquired using direct electron detectors is, therefore, paramount for quantitative analysis of the experimental images. We have developed a new open-source Python package to accurately model any single layer direct electron detector for low and high fluence imaging conditions, including a means to validate against experimental data through computation of modulation transfer function and detective quantum efficiency.
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Affiliation(s)
- Gearóid Liam Mangan
- Physics Department, Faculty of Science and Engineering, University of Limerick, Limerick V94 T9PX, Ireland
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
| | - Grigore Moldovan
- Point Electronic Gmbh, Erich-Neuss-Weg 15, Halle (Saale) D-06120, Germany
| | - Andrew Stewart
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, UK
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Holmestad R, Thronsen E, Kawahara Y, Bergh T, Sørhaug JA, Hell CM, Bjørge R, Christiansen EF, Kaneko K, Marioara CD. Nucleation and Phase Development of Precipitates in Age-hardenable Aluminium Alloys Studied by 4D-STEM. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:305-306. [PMID: 37613473 DOI: 10.1093/micmic/ozad067.141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Randi Holmestad
- Deptof Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | | | - Yasuhito Kawahara
- Deptof Materials Science and Engineering, Kyushu University, Fukuoka, Japan
| | - Tina Bergh
- Dept of Chemical Engineering, NTNU, Trondheim, Norway
| | - Jørgen A Sørhaug
- Deptof Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Christoph M Hell
- Deptof Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Ruben Bjørge
- Deptof Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Deptof Materials Science and Engineering, Kyushu University, Fukuoka, Japan
| | - Emil F Christiansen
- Deptof Physics, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Kenji Kaneko
- Materials and Nanotechnology, SINTEF Industry, Trondheim, Norway
| | - Calin D Marioara
- Deptof Materials Science and Engineering, Kyushu University, Fukuoka, Japan
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37
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Calderon S, Dickey EC. Structural Modification in B-doped AlN Ferroelectric Films by STEM-DPC. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:1796-1797. [PMID: 37613984 DOI: 10.1093/micmic/ozad067.929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- S Calderon
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Elizabeth C Dickey
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, United States
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38
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Calderon S, Hayden J, Baksa SM, Tzou W, Trolier-McKinstry S, Dabo I, Maria JP, Dickey EC. Atomic-scale polarization switching in wurtzite ferroelectrics. Science 2023; 380:1034-1038. [PMID: 37289886 DOI: 10.1126/science.adh7670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 05/10/2023] [Indexed: 06/10/2023]
Abstract
Ferroelectric wurtzites have the potential to revolutionize modern microelectronics because they are easily integrated with multiple mainstream semiconductor platforms. However, the electric fields required to reverse their polarization direction and unlock electronic and optical functions need substantial reduction for operational compatibility with complementary metal-oxide semiconductor (CMOS) electronics. To understand this process, we observed and quantified real-time polarization switching of a representative ferroelectric wurtzite (Al0.94B0.06N) at the atomic scale with scanning transmission electron microscopy. The analysis revealed a polarization reversal model in which puckered aluminum/boron nitride rings in the wurtzite basal planes gradually flatten and adopt a transient nonpolar geometry. Independent first-principles simulations reveal the details and energetics of the reversal process through an antipolar phase. This model and local mechanistic understanding are a critical initial step for property engineering efforts in this emerging material class.
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Affiliation(s)
- Sebastian Calderon
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - John Hayden
- The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA
| | - Steven M Baksa
- The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA
| | - William Tzou
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Susan Trolier-McKinstry
- The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA
| | - Ismaila Dabo
- The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA
| | - Jon-Paul Maria
- The Pennsylvania State University, Department of Materials Science and Engineering and Materials Research Institute, University Park, PA 16802, USA
| | - Elizabeth C Dickey
- Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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39
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Zhang S, Yin L, Li Q, Wang S, Wang W, Du Y. Laves phase Ir 2Sm intermetallic nanoparticles as a highly active electrocatalyst for acidic oxygen evolution reaction. Chem Sci 2023; 14:5887-5893. [PMID: 37293647 PMCID: PMC10246678 DOI: 10.1039/d3sc01052j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Accepted: 04/15/2023] [Indexed: 06/10/2023] Open
Abstract
Rare earth (RE) intermetallic nanoparticles (NPs) are significant for fundamental explorations and promising for practical applications in electrocatalysis. However, they are difficult to synthesize because of the unusually low reduction potential and extremely high oxygen affinity of RE metal-oxygen bonds. Herein, intermetallic Ir2Sm NPs were firstly synthesized on graphene as a superior acidic oxygen evolution reaction (OER) catalyst. It was verified that intermetallic Ir2Sm is a new phase belonging to the C15 cubic MgCu2 type in the Laves phase family. Meanwhile, intermetallic Ir2Sm NPs achieved a mass activity of 1.24 A mgIr-1 at 1.53 V and stability of 120 h at 10 mA cm-2 in 0.5 M H2SO4 electrolyte, which corresponds to a 5.6-fold and 12-fold enhancement relative to Ir NPs. Experimental results together with density functional theory (DFT) calculations show that in the structurally ordered intermetallic Ir2Sm NPs, the alloying of Sm with Ir atoms modulates the electronic nature of Ir, thereby reducing the binding energy of the oxygen-based intermediate, resulting in faster kinetics and enhanced OER activity. This study provides a new perspective for the rational design and practical application of high-performance RE alloy catalysts.
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Affiliation(s)
- Shuai Zhang
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Haihe Laboratory of Sustainable Chemical Transformations, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University Tianjin 300350 China
| | - Leilei Yin
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Haihe Laboratory of Sustainable Chemical Transformations, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University Tianjin 300350 China
| | - Qingqing Li
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Haihe Laboratory of Sustainable Chemical Transformations, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University Tianjin 300350 China
| | - Siyuan Wang
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Haihe Laboratory of Sustainable Chemical Transformations, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University Tianjin 300350 China
| | - Weihua Wang
- College of Electronic Information and Optical Engineering, Nankai University Tianjin 300350 China
| | - Yaping Du
- Tianjin Key Lab for Rare Earth Materials and Applications, Center for Rare Earth and Inorganic Functional Materials, Haihe Laboratory of Sustainable Chemical Transformations, Smart Sensing Interdisciplinary Science Center, School of Materials Science and Engineering, National Institute for Advanced Materials, Nankai University Tianjin 300350 China
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40
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Kim H, Choi H, Oh J, Lee S, Kwon H, Park ES, Lee S, Lee GD, Kim M, Han HN. Elucidating the role of a unique step-like interfacial structure of η 4 precipitates in Al-Zn-Mg alloy. SCIENCE ADVANCES 2023; 9:eadf7426. [PMID: 37267366 PMCID: PMC10413671 DOI: 10.1126/sciadv.adf7426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 04/27/2023] [Indexed: 06/04/2023]
Abstract
Al-Zn-Mg alloys are widely used in the transportation industry owing to their high strength-to-weight ratio. In these alloys, the main strengthening mechanism is precipitation hardening that occurs because of the formation of nano-sized precipitates. Herein, an interfacial structure of η4 precipitates, one of the main precipitates in these alloys, is revealed using aberration-corrected scanning transmission electron microscopy and first-principles calculations. These precipitates exhibit a pseudo-periodic steps and bridges. The results of this study demonstrate that the peculiar interface structure of η4/Al relieves the strain energy of η4 precipitates thus stabilizing them. The atomistic role of this interfacial structure in the nucleation and growth of the precipitates is elucidated. This study paves the way for tailoring the mechanical properties of alloys by controlling their precipitation kinetics.
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Affiliation(s)
| | | | - Juhyun Oh
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Sangmin Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Ho Kwon
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | | | - Sungwoo Lee
- Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Gun-Do Lee
- Corresponding author. (H.N.H.); (M.K.); (G.-D.L.)
| | - Miyoung Kim
- Corresponding author. (H.N.H.); (M.K.); (G.-D.L.)
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41
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Yan X, Jiang Y, Jin Q, Yao T, Wang W, Tao A, Gao C, Li X, Chen C, Ye H, Ma XL. Interfacial interaction and intense interfacial ultraviolet light emission at an incoherent interface. Nat Commun 2023; 14:2788. [PMID: 37188706 DOI: 10.1038/s41467-023-38548-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 05/08/2023] [Indexed: 05/17/2023] Open
Abstract
Incoherent interfaces with large mismatches usually exhibit very weak interfacial interactions so that they rarely generate intriguing interfacial properties. Here we demonstrate unexpected strong interfacial interactions at the incoherent AlN/Al2O3 (0001) interface with a large mismatch by combining transmission electron microscopy, first-principles calculations, and cathodoluminescence spectroscopy. It is revealed that strong interfacial interactions have significantly tailored the interfacial atomic structure and electronic properties. Misfit dislocation networks and stacking faults are formed at this interface, which is rarely observed at other incoherent interfaces. The band gap of the interface reduces significantly to ~ 3.9 eV due to the competition between the elongated Al-N and Al-O bonds across the interface. Thus this incoherent interface can generate a very strong interfacial ultraviolet light emission. Our findings suggest that incoherent interfaces can exhibit strong interfacial interactions and unique interfacial properties, thereby opening an avenue for the development of related heterojunction materials and devices.
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Affiliation(s)
- Xuexi Yan
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Yixiao Jiang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Qianqian Jin
- Center for the Structure of Advanced Matter, School of Electronic Engineering, Guangxi University of Science and Technology, Liuzhou, 545006, China
| | - Tingting Yao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Weizhen Wang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Ang Tao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Chunyang Gao
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Xiang Li
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China
| | - Chunlin Chen
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China.
- Ji Hua Laboratory, Foshan, 528200, China.
| | | | - Xiu-Liang Ma
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, School of Material Science and Engineering, University of Science and Technology of China, Shenyang, 110016, China.
- Bay Area Center for Electron Microscopy, Songshan Lake Materials Laboratory, Dongguan, 523808, China.
- Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
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42
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Kim HS, An JS, Bae HB, Chung SY. Atomic-scale observation of premelting at 2D lattice defects inside oxide crystals. Nat Commun 2023; 14:2255. [PMID: 37081020 PMCID: PMC10119109 DOI: 10.1038/s41467-023-37977-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 04/05/2023] [Indexed: 04/22/2023] Open
Abstract
Since two major criteria for melting were proposed by Lindemann and Born in the early 1900s, many simulations and observations have been carried out to elucidate the premelting phenomena largely at the crystal surfaces and grain boundaries below the bulk melting point. Although dislocations and clusters of vacancies and interstitials were predicted as possible origins to trigger the melting, experimental direct observations demonstrating the correlation of premelting with lattice defects inside a crystal remain elusive. Using atomic-column-resolved imaging with scanning transmission electron microscopy in polycrystalline BaCeO3, here we clarify the initiation of melting at two-dimensional faults inside the crystals below the melting temperature. In particular, melting in a layer-by-layer manner rather than random nucleation at the early stage was identified as a notable finding. Emphasizing the value of direct atomistic observation, our study suggests that lattice defects inside crystals should not be overlooked as preferential nucleation sites for phase transformation including melting.
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Affiliation(s)
- Hye-Sung Kim
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
- Korea Institute of Energy Research, Daejeon, 34129, Korea
| | - Ji-Sang An
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Hyung Bin Bae
- KAIST Analysis Center, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea
| | - Sung-Yoon Chung
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Korea.
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43
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Ran K, Barthel J, Jin L, Park D, Buchheit A, Neuhaus K, Baumann S, Meulenberg WA, Mayer J. Direct Visualization of Distorted Twin Boundaries in Ce-Doped GdFeO 3. NANO LETTERS 2023; 23:2945-2951. [PMID: 36972518 DOI: 10.1021/acs.nanolett.3c00318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Utilizing advanced transmission electron microscopy (TEM), the structure at the (110)-type twin boundary (TB) of Ce-doped GdFeO3 (C-GFO) has been investigated with picometer precision. Such a TB is promising to generate local ferroelectricity within a paraelectric system, while precise knowledge about its structure is still largely missing. In this work, a direct measurement of the cation off-centering with respect to the neighboring oxygen is enabled by integrated differential phase contrast (iDPC) imaging, and up to 30 pm Gd off-centering is highly localized at the TB. Further electron energy loss spectroscopy (EELS) analysis demonstrates a slight accumulation of oxygen vacancies at the TB, a self-balanced behavior of Ce at the Gd sites, and a mixed occupation of Fe2+ and Fe3+ at the Fe sites. Our results provide an informative picture with atomic details at the TB of C-GFO, which is indispensable to further push the potential of grain boundary engineering.
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Affiliation(s)
- Ke Ran
- Central Facility for Electron Microscopy GFE, RWTH Aachen University, 52074 Aachen, Germany
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Juri Barthel
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Lei Jin
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Daesung Park
- Physikalisch-Technische Bundesanstalt PTB, 38116 Braunschweig, Germany
| | - Annika Buchheit
- Institute of Energy and Climate Research IEK-12, Forschungszentrum Jülich GmbH, 48149 Münster, Germany
| | - Kerstin Neuhaus
- Institute of Energy and Climate Research IEK-12, Forschungszentrum Jülich GmbH, 48149 Münster, Germany
| | - Stefan Baumann
- Institute of Energy and Climate Research IEK-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Wilhelm A Meulenberg
- Institute of Energy and Climate Research IEK-1, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Faculty of Science and Technology, Inorganic Membranes, University of Twente, 7500 AE Enschede, The Netherlands
| | - Joachim Mayer
- Central Facility for Electron Microscopy GFE, RWTH Aachen University, 52074 Aachen, Germany
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons ER-C, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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44
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Liang Z, Song D, Ge B. Optimizing experimental parameters of integrated differential phase contrast (iDPC) for atomic resolution imaging. Ultramicroscopy 2023; 246:113686. [PMID: 36682324 DOI: 10.1016/j.ultramic.2023.113686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 11/30/2022] [Accepted: 01/16/2023] [Indexed: 01/19/2023]
Abstract
Integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM) technique has been well developed for studying atomic structures at sub-Å resolution with the capability of simultaneously imaging heavy and light atoms even at an extremely low electron dose. As a direct phase contrast imaging technique, atomic resolution iDPC-STEM is sensitive to the imaging conditions. Although great achievements have been made both in aspect of theory and experiments, the influence of experimental parameters on the contrast of atomic resolution iDPC-STEM images has not been systematically investigated. Here, we perform the iDPC-STEM simulations on the prototypical example of SrTiO3 with respect to the routine experimental factors, including the defocus, specimen thickness, accelerating voltage, convergence angle, collection angle, sample tilt and electron dose. Through the evaluation of image contrast and atom column intensity, the parameters are discussed to improve the image contrast and the visibility of light elements. Moreover, the dose-dependent simulations demonstrate the advantage of low dose iDPC-STEM imaging over other conventional STEM modes. Our results provide a practical guideline to experimentally obtain accessible atomic resolution iDPC-STEM images.
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Affiliation(s)
- Zhiyao Liang
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China
| | - Dongsheng Song
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
| | - Binghui Ge
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Institutes of Physical Science and Information Technology, Anhui University, Hefei 230601, China.
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45
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Robinson AW, Wells J, Nicholls D, Moshtaghpour A, Chi M, Kirkland AI, Browning ND. Towards real-time STEM simulations through targeted subsampling strategies. J Microsc 2023; 290:53-66. [PMID: 36800515 DOI: 10.1111/jmi.13177] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 02/14/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023]
Abstract
Scanning transmission electron microscopy images can be complex to interpret on the atomic scale as the contrast is sensitive to multiple factors such as sample thickness, composition, defects and aberrations. Simulations are commonly used to validate or interpret real experimental images, but they come at a cost of either long computation times or specialist hardware such as graphics processing units. Recent works in compressive sensing for experimental STEM images have shown that it is possible to significantly reduce the amount of acquired signal and still recover the full image without significant loss of image quality, and therefore it is proposed here that similar methods can be applied to STEM simulations. In this paper, we demonstrate a method that can significantly increase the efficiency of STEM simulations through a targeted sampling strategy, along with a new approach to independently subsample each frozen phonon layer. We show the effectiveness of this method by simulating a SrTiO3 grain boundary and monolayer 2H-MoS2 containing a sulphur vacancy using the abTEM software. We also show how this method is not limited to only traditional multislice methods, but also increases the speed of the PRISM simulation method. Furthermore, we discuss the possibility for STEM simulations to seed the acquisition of real data, to potentially lead the way to self-driving (correcting) STEM.
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Affiliation(s)
- Alex W Robinson
- Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK
| | - Jack Wells
- Distributed Algorithms Centre for Doctoral Training, University of Liverpool, Liverpool, UK
| | - Daniel Nicholls
- Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK
| | - Amirafshar Moshtaghpour
- Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.,Correlated Imaging Group, Rosalind Franklin Institute, Didcot, UK
| | - Miaofang Chi
- Chemical Science Division, Centre for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States
| | - Angus I Kirkland
- Correlated Imaging Group, Rosalind Franklin Institute, Didcot, UK.,Department of Materials, University of Oxford, Oxford, UK
| | - Nigel D Browning
- Department of Mechanical, Materials and Aerospace Engineering, University of Liverpool, Liverpool, UK.,Materials Sciences, Physical and Computational Science Directorate, Pacific Northwest National Laboratory, Richland, Washington, United States.,Research and Development, Sivananthan Laboratories, Bolingbrook, Illinois, United States
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46
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Seifer S. Sampling theory perspective on tomographic tilt increment schemes. Ultramicroscopy 2023; 245:113669. [PMID: 36566528 DOI: 10.1016/j.ultramic.2022.113669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 10/26/2022] [Accepted: 12/17/2022] [Indexed: 12/23/2022]
Abstract
Given a limited radiation exposure to be distributed over a discrete number of tilted projections in tomography, the optimal collection of information depends on the tilt increment scheme. Relying on principles of sampling theory, several tilt increment schemes can be compared and quantified. Following reasoning of Saxton, a revised scheme is offered in which the tilt angle increments Δθn are proportional to 1/cosθn. The revised scheme is preferable according to matrix analysis and simulations of geometrical optics. For thin specimens, applying a cosine sampling grid similar to Hoppe's scheme can improve the results. A realistic case is examined by Dr. Probe simulation of a scanning transmission electron microscope (STEM) for an atomic model adapted from the Ferritin protein molecule. Optimal reconstruction methods that are tested include the direct algebraic method, iterative reconstruction, and a new deconvolution-based weighted back-projection, which resembles the correction filter technique in signal recovery from sub-sampled data. A non-linear correction may be accounted for by iteration of the simulation with an ad-hoc atomic model.
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Affiliation(s)
- Shahar Seifer
- Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
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47
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Kim S, Miyauchi R, Sato Y, Nam H, Fujii I, Ueno S, Kuroiwa Y, Wada S. Piezoelectric Actuation Mechanism Involving Extrinsic Nanodomain Dynamics in Lead-Free Piezoelectrics. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208717. [PMID: 36609990 DOI: 10.1002/adma.202208717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Piezoelectric materials play a key role in applications, while there are physically open questions. The physical origin of piezoelectricity is understood as the sum of contributions from intrinsic effects on lattice dynamics and those from extrinsic effects on ferroic-domain dynamics, but there is an incomplete understanding that all but intrinsic effects are classified as extrinsic effects. Therefore, the accurate classification of extrinsic effects is important for understanding the physical origin of piezoelectricity. In this work, high-energy synchrotron radiation X-ray diffraction is utilized to measure the response of BiFeO3 -BaTiO3 piezoelectrics and the intrinsic/extrinsic contribution to electric fields. It is found from crystal structure and intrinsic/extrinsic contribution, using the analysis involving structure refinement with various structural model and micromechanics-based calculations, that Bi3+ -ion disordering is important for realization of piezoelectricity and nanodomains. Here, an extrinsic effect on the rearrangement of nanodomains is suggested. The nanodomains, which are formed by the locally distorted structure around the A-site by Bi-ion disordering, can significantly deform the material in the BiFeO3 -BaTiO3 system, which contributes to the piezoelectric actuation mechanism apart from the extrinsic effect on ferroic-domain dynamics. Bi-ion disordering plays an important role in realizing piezoelectricity and nanodomains and can provide essential material design clues to develop next-generation Bi-based lead-free piezoelectric ceramics.
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Affiliation(s)
- Sangwook Kim
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashihiroshima, Hiroshima, 739-8526, Japan
| | - Ryuki Miyauchi
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, 819-0395, Japan
| | - Yukio Sato
- Department of Materials Science and Engineering, Graduate School of Engineering, Kyushu University, Fukuoka, 819-0395, Japan
| | - Hyunwook Nam
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi, 400-8510, Japan
| | - Ichiro Fujii
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi, 400-8510, Japan
| | - Shintaro Ueno
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi, 400-8510, Japan
| | - Yoshihiro Kuroiwa
- Graduate School of Advanced Science and Engineering, Hiroshima University, Higashihiroshima, Hiroshima, 739-8526, Japan
| | - Satoshi Wada
- Graduate Faculty of Interdisciplinary Research, University of Yamanashi, Kofu, Yamanashi, 400-8510, Japan
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48
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Sokolikova MS, Cheng G, Och M, Palczynski P, El Hajraoui K, Ramasse QM, Mattevi C. Tuning the 1T'/2H phases in W xMo 1-xSe 2 nanosheets. NANOSCALE 2023; 15:2714-2725. [PMID: 36651927 PMCID: PMC9909680 DOI: 10.1039/d2nr05631c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Controlling materials' morphology, crystal phase and chemical composition at the atomic scale has become central in materials research. Wet chemistry approaches have great potential in directing the material crystallisation process to achieve tuneable chemical compositions as well as to target specific crystal phases. Herein, we report the compositional and crystal phase tuneability achieved in the quasi-binary WxMo1-xSe2 system with chemical and crystal phase mixing down to the atomic level. A series of WxMo1-xSe2 solid solutions in the form of nanoflowers with atomically thin petals were obtained via a direct colloidal reaction by systematically varying the ratios of transition metal precursors. We investigate the effect of selenium precursor on the morphology of the WxMo1-xSe2 material and show how using elemental selenium can enable the formation of larger and distinct nanoflowers. While the synthesised materials are compositionally homogeneous, they exhibit crystal phase heterogeneity with the co-existing domains of the 1T' and 2H crystal phases, and with evidence of MoSe2 in the metastable 1T' phase. We show at single atom level of resolution, that tungsten and molybdenum can be found in both the 1T' and 2H lattices. The formation of heterophase 1T'/2H WxMo1-xSe2 electrocatalysts allowed for a considerable improvement in the activity for the acidic hydrogen evolution reaction (HER) compared to pristine, 1T'-dominated, WSe2. This work can pave the way towards engineered functional nanomaterials where properties, such as electronic and catalytic, have to be controlled at the atomic scale.
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Affiliation(s)
| | - Gang Cheng
- Department of Materials, Imperial College London, London SW7 2AZ, UK.
| | - Mauro Och
- Department of Materials, Imperial College London, London SW7 2AZ, UK.
| | - Pawel Palczynski
- Department of Materials, Imperial College London, London SW7 2AZ, UK.
| | - Khalil El Hajraoui
- SuperSTEM Laboratory, SciTech Daresbury, Keckwick Lane, Daresbury WA4 4AD, UK
- York NanoCentre & Department of Physics, University of York, York YO10 5DD, UK
| | - Quentin M Ramasse
- SuperSTEM Laboratory, SciTech Daresbury, Keckwick Lane, Daresbury WA4 4AD, UK
- School of Physics and Astronomy & School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Cecilia Mattevi
- Department of Materials, Imperial College London, London SW7 2AZ, UK.
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49
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Fang H, Wu S, Ayvali T, Zheng J, Fellowes J, Ho PL, Leung KC, Large A, Held G, Kato R, Suenaga K, Reyes YIA, Thang HV, Chen HYT, Tsang SCE. Dispersed surface Ru ensembles on MgO(111) for catalytic ammonia decomposition. Nat Commun 2023; 14:647. [PMID: 36746965 PMCID: PMC9902439 DOI: 10.1038/s41467-023-36339-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 01/24/2023] [Indexed: 02/08/2023] Open
Abstract
Ammonia is regarded as an energy vector for hydrogen storage, transport and utilization, which links to usage of renewable energies. However, efficient catalysts for ammonia decomposition and their underlying mechanism yet remain obscure. Here we report that atomically-dispersed Ru atoms on MgO support on its polar (111) facets {denoted as MgO(111)} show the highest rate of ammonia decomposition, as far as we are aware, than all catalysts reported in literature due to the strong metal-support interaction and efficient surface coupling reaction. We have carefully investigated the loading effect of Ru from atomic form to cluster/nanoparticle on MgO(111). Progressive increase of surface Ru concentration, correlated with increase in specific activity per metal site, clearly indicates synergistic metal sites in close proximity, akin to those bimetallic N2 complexes in solution are required for the stepwise dehydrogenation of ammonia to N2/H2, as also supported by DFT modelling. Whereas, beyond surface doping, the specific activity drops substantially upon the formation of Ru cluster/nanoparticle, which challenges the classical view of allegorically higher activity of coordinated Ru atoms in cluster form (B5 sites) than isolated sites.
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Affiliation(s)
- Huihuang Fang
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Simson Wu
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Tugce Ayvali
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Jianwei Zheng
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Joshua Fellowes
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Ping-Luen Ho
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Kwan Chee Leung
- grid.4991.50000 0004 1936 8948The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR UK
| | - Alexander Large
- grid.18785.330000 0004 1764 0696Diamond Light Source, Didcot, OX11 0DE UK
| | - Georg Held
- grid.18785.330000 0004 1764 0696Diamond Light Source, Didcot, OX11 0DE UK
| | - Ryuichi Kato
- grid.208504.b0000 0001 2230 7538National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, 305-8565 Japan
| | - Kazu Suenaga
- grid.208504.b0000 0001 2230 7538National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, 305-8565 Japan
| | - Yves Ira A. Reyes
- grid.38348.340000 0004 0532 0580Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 300044 Taiwan
| | - Ho Viet Thang
- grid.444910.c0000 0001 0448 6667The University of Danang, University of Science and Technology, DaNang, 550000 Vietnam
| | - Hsin-Yi Tiffany Chen
- grid.38348.340000 0004 0532 0580Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 300044 Taiwan ,grid.38348.340000 0004 0532 0580College of Semiconductor Research, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Road, Hsinchu, 300044 Taiwan ,grid.38348.340000 0004 0532 0580Department of Material Science and Engineering, National Tsing Hua University, Hsinchu, 300044 Taiwan
| | - Shik Chi Edman Tsang
- The Wolfson Catalysis Centre, Department of Chemistry, University of Oxford, Oxford, OX1 3QR, UK.
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50
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Johnston-Peck AC, Maier RA. Adlayer formation on C-plane (0001) and R-plane ( 1 1 ‒ 0 2 ) Al 2O 3 surfaces. JOURNAL OF THE AMERICAN CERAMIC SOCIETY. AMERICAN CERAMIC SOCIETY 2023; 106:1490-1499. [PMID: 36761689 PMCID: PMC9903351 DOI: 10.1111/jace.18814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/17/2022] [Indexed: 06/18/2023]
Abstract
Adlayers on C-plane (0001) and R-plane ( 1 1 ‒ 02 ) terminated surfaces of corundum phase aluminum oxide were synthesized by annealing mixtures of two oxide powders, aluminum oxide with an additive. Using high-angle annular dark field scanning transmission electron microscopy, the adsorbed layers were characterized, and image simulations aided interpretation of the results. The adlayers were pseudomorphic, one atomic layer thick and with a fractional site occupancy. Atomic positions of the adlayer atoms relaxed and changed relative to the bulk structure, where there is evidence that the magnitude of the relaxation is sensitive to the ionic radius of the adsorbate. The pseudomorphic adlayer structure formed for different elements including, but not limited to, the lanthanides (i.e., Ge, Ba and Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm).
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Affiliation(s)
- Aaron C Johnston-Peck
- Material Measurement Laboratory National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899 United States
| | - Russell A Maier
- Material Measurement Laboratory National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899 United States
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