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Smeaton MA, Schnitzer N, Zheng H, Mitchell JF, Kourkoutis LF. Influence of Light Atoms on Quantification of Atomic Column Positions in Distorted Perovskites with HAADF-STEM. NANO LETTERS 2023. [PMID: 37429013 DOI: 10.1021/acs.nanolett.3c01140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/12/2023]
Abstract
Measurement of picometer-scale atomic displacements by aberration-corrected STEM has become invaluable in the study of crystalline materials, where it can elucidate ordering mechanisms and local heterogeneities. HAADF-STEM imaging, often used for such measurements due to its atomic number contrast, is generally considered insensitive to light atoms such as oxygen. Light atoms, however, still affect the propagation of the electron beam in the sample and, therefore, the collected signal. Here, we demonstrate experimentally and through simulations that cation sites in distorted perovskites can appear to be displaced by several picometers from their true positions in shared cation-anion columns. The effect can be decreased through careful choice of sample thickness and beam voltage or can be entirely avoided if the experiment allows reorientation of the crystal along a more favorable zone axis. Therefore, it is crucial to consider the possible effects of light atoms and crystal symmetry and orientation when measuring atomic positions.
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Affiliation(s)
- Michelle A Smeaton
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Noah Schnitzer
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Hong Zheng
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - J F Mitchell
- Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Lena F Kourkoutis
- School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute for Nanoscale Science, Cornell University, Ithaca, New York 14853, United States
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2
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Zhang Y, Yu R, Zhu J. Displacement separation analysis from atomic-resolution images. Ultramicroscopy 2021; 232:113404. [PMID: 34656896 DOI: 10.1016/j.ultramic.2021.113404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 09/26/2021] [Accepted: 10/03/2021] [Indexed: 11/16/2022]
Abstract
Structural distortions frequently occur in materials, either periodically (ferroelectric or antiferroelectric) or in local areas (domain boundaries, surfaces/interfaces, dislocations). Measuring atomic displacements from an average lattice is of crucial importance for analyzing structural distortions and their connections to physical properties. Conventionally, the displacements are measured atom-by-atom by fitting atomic-resolution images with two-dimensional gaussian functions. Here, we exhibit an efficient method, named Displacement Separation Analysis, DSA in short, to directly separate atomic displacements from an average lattice based on Fourier space filtering. Using antiferroelectric AgNbO3 as a model system, we demonstrate the consistence between DSA and gaussian fitting. The suppression of polarization at interfacial region of h-LuFeO3/α-Al2O3 heterostructure and the emergence of modulation structure in LuFe2O4+x is then revealed using DSA, attesting the implication of DSA in unveiling structural distortions either locally or periodically. Inspired by the simple principle of DSA, such method can be used for any atomic-resolution images, including TEM, STM, and AFM images to exhibit the atomic displacement intuitively.
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Affiliation(s)
- Yang Zhang
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China; Ji Hua Laboratory, Foshan, 528299, P.R. China; State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, P.R. China
| | - Rong Yu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
| | - Jing Zhu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, P.R. China.
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Deng S, Li J, Småbråten DR, Shen S, Wang W, Zhao J, Tao J, Aschauer U, Chen J, Zhu Y, Zhu J. Critical Role of Sc Substitution in Modulating Ferroelectricity in Multiferroic LuFeO 3. NANO LETTERS 2021; 21:6648-6655. [PMID: 34283627 DOI: 10.1021/acs.nanolett.1c02123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Understanding how individual dopants or substitutional atoms interact with host lattices enables us to manipulate, control, and improve the functionality of materials. However, because of the intimate coupling among various degrees of freedom in multiferroics, the atomic-scale influence of individual foreign atoms has remained elusive. Here, we unravel the critical roles of individual Sc substitutional atoms in modulating ferroelectricity at the atomic scale of typical multiferroics, Lu1-xScxFeO3, by combining advanced microscopy and theoretical studies. Atomic variations in polar displacement of intriguing topological vortex domains stabilized by Sc substitution are directly correlated with Sc atom-mediated local chemical and electronic fluctuations. The local FeO5 trimerization magnitude and Lu/Sc-O hybridization strength are found to be significantly reinforced by Sc, clarifying the origin of the strong dependence of improper ferroelectricity on Sc content. This study could pave the way for correlating dopant-regulated atomic-scale local structures with global properties to engineer emergent functionalities of numerous chemically doped functional materials.
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Affiliation(s)
- Shiqing Deng
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Jun Li
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Didrik R Småbråten
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Shoudong Shen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Wenbin Wang
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Jun Zhao
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Jing Tao
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Ulrich Aschauer
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Jun Chen
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Jing Zhu
- School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
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Cheng S, Li X, Xu C, Liu Y, Beleggia M, Wu L, Wang W, Petrovic C, Bellaiche L, Tao J, Zhu Y. Coexistence and Coupling of Multiple Charge Orderings and Spin States in Hexagonal Ferrite. NANO LETTERS 2021; 21:5782-5787. [PMID: 34170143 DOI: 10.1021/acs.nanolett.1c01624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The coupling between charge and spin orderings in strongly correlated systems plays a crucial role in fundamental physics and device applications. As a candidate of multiferroic materials, LuFe2O4 with a nominal Fe2.5+ valence state has the potential for strong charge-spin interactions; however, these interactions have not been fully understood until now. Here, combining complementary characterization methods with theoretical calculations, two types of charge orderings with distinct magnetic properties are revealed. The ground states of LuFe2O4 are decided by the parallel/antiparallel coupling of both charge and spin orderings in the adjacent FeO double layers. Whereas the ferroelectric charge ordering remains ferrimagnetic below 230 K, the antiferroelectric ordering undergoes antiferromagnetic-ferrimagnetic-paramagnetic transitions from 2 K to room temperature. This study demonstrates the unique aspects of strong spin-charge coupling within LuFe2O4. Our results shed light on the coexistence and competing nature of orderings in quantum materials.
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Affiliation(s)
- Shaobo Cheng
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Xing Li
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
- Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
| | - Changsong Xu
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Yu Liu
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Marco Beleggia
- DTU Nanolab, Technical University of Denmark, Kongens Lyngby 2800, Denmark
| | - Lijun Wu
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Wenbin Wang
- Institute for Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Cedomir Petrovic
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Laurent Bellaiche
- Physics Department and Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701, United States
| | - Jing Tao
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Yimei Zhu
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, United States
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Zhang Y, Wang W, Xing W, Cheng S, Deng S, Angst M, Yu CP, Lan F, Cheng Z, Mandrus D, Sales B, Shen J, Zhong X, Tai NH, Yu R, Zhu J. Effect of Oxygen Interstitial Ordering on Multiple Order Parameters in Rare Earth Ferrite. PHYSICAL REVIEW LETTERS 2019; 123:247601. [PMID: 31922871 DOI: 10.1103/physrevlett.123.247601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 09/09/2019] [Indexed: 06/10/2023]
Abstract
Oxygen interstitials and vacancies play a key role in modulating the microstructure and properties of nonstoichiometric oxide systems, such as those used for superconductors and multiferroics. Key to understanding the tuning mechanisms resulting from oxygen doping is a knowledge of the precise positions of these lattice defects, and of the interaction both between these defects and with many order parameters. Here, we report how such information can, for the first time, be obtained from a sample of LuFe_{2}O_{4.22} using a range of techniques including advanced electron microscopy, atomic-resolution spectroscopy, and density functional theory calculations. The results provide quantitative atomic details of the crystal unit cell, together with a description of the ferroelastic, ferroelectric, and ferromagnetic order parameters. We elucidate also the interaction between these order parameters and the positions of the oxygen interstitials in the oxygen-enriched sample. The comprehensive analysis of oxygen interstitial ordering provides insights into understanding the coupling among different degrees of freedom in rare earth ferrites and demonstrates that oxygen content regulation is a powerful tool for tuning the microstructure and properties for this class of quantum material.
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Affiliation(s)
- Yang Zhang
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wenbin Wang
- Institute of Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
| | - Wandong Xing
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shaobo Cheng
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Shiqing Deng
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Manuel Angst
- Jülich Centre for Neutron Science JCNS and Peter Grünberg Institut PGI, JARA-FIT, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Chu-Ping Yu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
- Department of Materials Science and Engineering National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Fanli Lan
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Zhiying Cheng
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - David Mandrus
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Brian Sales
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Jian Shen
- Institute of Nanoelectronic Devices and Quantum Computing, Fudan University, Shanghai 200433, China
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China
| | - Xiaoyan Zhong
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Nyan-Hwa Tai
- Department of Materials Science and Engineering National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Rong Yu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
| | - Jing Zhu
- National Center for Electron Microscopy in Beijing, Key Laboratory of Advanced Materials (MOE), The State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People's Republic of China
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