1
|
Jani H, Harrison J, Hooda S, Prakash S, Nandi P, Hu J, Zeng Z, Lin JC, Godfrey C, Omar GJ, Butcher TA, Raabe J, Finizio S, Thean AVY, Ariando A, Radaelli PG. Spatially reconfigurable antiferromagnetic states in topologically rich free-standing nanomembranes. NATURE MATERIALS 2024; 23:619-626. [PMID: 38374414 PMCID: PMC11068574 DOI: 10.1038/s41563-024-01806-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 01/11/2024] [Indexed: 02/21/2024]
Abstract
Antiferromagnets hosting real-space topological textures are promising platforms to model fundamental ultrafast phenomena and explore spintronics. However, they have only been epitaxially fabricated on specific symmetry-matched substrates, thereby preserving their intrinsic magneto-crystalline order. This curtails their integration with dissimilar supports, restricting the scope of fundamental and applied investigations. Here we circumvent this limitation by designing detachable crystalline antiferromagnetic nanomembranes of α-Fe2O3. First, we show-via transmission-based antiferromagnetic vector mapping-that flat nanomembranes host a spin-reorientation transition and rich topological phenomenology. Second, we exploit their extreme flexibility to demonstrate the reconfiguration of antiferromagnetic states across three-dimensional membrane folds resulting from flexure-induced strains. Finally, we combine these developments using a controlled manipulator to realize the strain-driven non-thermal generation of topological textures at room temperature. The integration of such free-standing antiferromagnetic layers with flat/curved nanostructures could enable spin texture designs via magnetoelastic/geometric effects in the quasi-static and dynamical regimes, opening new explorations into curvilinear antiferromagnetism and unconventional computing.
Collapse
Affiliation(s)
- Hariom Jani
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
- Department of Physics, National University of Singapore, Singapore, Singapore.
| | - Jack Harrison
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Sonu Hooda
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
| | - Saurav Prakash
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Proloy Nandi
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Junxiong Hu
- Department of Physics, National University of Singapore, Singapore, Singapore.
| | - Zhiyang Zeng
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Jheng-Cyuan Lin
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Charles Godfrey
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK
| | - Ganesh Ji Omar
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Tim A Butcher
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Jörg Raabe
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland
| | - Simone Finizio
- Swiss Light Source, Paul Scherrer Institut, Villigen, Switzerland.
| | - Aaron Voon-Yew Thean
- Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, Singapore
| | - A Ariando
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Integrative Sciences and Engineering Programme, National University of Singapore, Singapore, Singapore.
| | - Paolo G Radaelli
- Clarendon Laboratory, Department of Physics, University of Oxford, Oxford, UK.
| |
Collapse
|
2
|
Wang Q, Gu Y, Chen C, Han L, Fayaz MU, Pan F, Song C. Strain-Induced Uphill Hydrogen Distribution in Perovskite Oxide Films. ACS APPLIED MATERIALS & INTERFACES 2024; 16:3726-3734. [PMID: 38197268 DOI: 10.1021/acsami.3c17472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Incorporating hydrogen into transition-metal oxides (TMOs) provides a facile and powerful way to manipulate the performances of TMOs, and thus numerous efforts have been invested in developing hydrogenation methods and exploring the property modulation via hydrogen doping. However, the distribution of hydrogen ions, which is a key factor in determining the physicochemical properties on a microscopic scale, has not been clearly illustrated. Here, focusing on prototypical perovskite oxide (NdNiO3 and La0.67Sr0.33MnO3) epitaxial films, we find that hydrogen distribution exhibits an anomalous "uphill" feature (against the concentration gradient) under tensile strain, namely, the proton concentration enhances upon getting farther from the hydrogen source. Distinctly, under a compressive strain state, hydrogen shows a normal distribution without uphill features. The epitaxial strain significantly influences the chemical lattice coupling and the energy profile as a function of the hydrogen doping position, thus dominating the hydrogen distribution. Furthermore, the strain-(H+) distribution relationship is maintained in different hydrogenation methods (metal-alkali treatment) which is first applied to perovskite oxides. The discovery of strain-dependent hydrogen distribution in oxides provides insights into tailoring the magnetoelectric and energy-conversion functionalities of TMOs via strain engineering.
Collapse
Affiliation(s)
- Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Youdi Gu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Lei Han
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Muhammad Umer Fayaz
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
| |
Collapse
|
3
|
Yang S, Son JW, Ju TS, Tran DM, Han HS, Park S, Park BH, Moon KW, Hwang C. Magnetic Skyrmion Transistor Gated with Voltage-Controlled Magnetic Anisotropy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208881. [PMID: 36511234 DOI: 10.1002/adma.202208881] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/27/2022] [Indexed: 06/17/2023]
Abstract
The paradigm shift of information carriers from charge to spin has long been awaited in modern electronics. The invention of the spin-information transistor is expected to be an essential building block for the future development of spintronics. Here, a proof-of-concept experiment of a magnetic skyrmion transistor working at room temperature, which has never been demonstrated experimentally, is introduced. With the spatially uniform control of magnetic anisotropy, the shape and topology of a skyrmion when passing the controlled area can be maintained. The findings will open a new route toward the design and realization of skyrmion-based spintronic devices in the near future.
Collapse
Affiliation(s)
- Seungmo Yang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Jong Wan Son
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Tae-Seong Ju
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Duc Minh Tran
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Hee-Sung Han
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sungkyun Park
- Department of Physics, Pusan National University, Busan, 46241, Republic of Korea
| | - Bae Ho Park
- Division of Quantum Phases and Devices, Department of Physics, Konkuk University, Seoul, 05029, Republic of Korea
| | - Kyoung-Woong Moon
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| | - Chanyong Hwang
- Quantum Spin Team, Korea Research Institute of Standards and Science, Daejeon, 34113, Republic of Korea
| |
Collapse
|
4
|
Ojo OP, Gunatilleke WDCB, Biacchi AJ, Wang H, Nolas GS. Thermal and Electronic Properties of Ba 2MnSe 3. Inorg Chem 2023; 62:3555-3561. [PMID: 36791428 DOI: 10.1021/acs.inorgchem.2c04048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The structural, thermal, and electronic properties of Ba2MnSe3 were investigated. Analysis of the low-temperature heat capacity revealed a low Debye temperature and a low average speed of sound that, together with the bonding in this material, result in a low thermal conductivity over a relatively large temperature range. Density functional theory and calculated electron localization were employed to investigate the electronic structure and bonding. Absorption and photoluminescence spectroscopy measurements corroborated our calculations and revealed a direct band gap of 1.75 eV. This study expands on our understanding of the physical properties of this material and reveals previously unascertained properties, the knowledge of which is imperative for any potential application of interest.
Collapse
Affiliation(s)
- Oluwagbemiga P Ojo
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| | | | - Adam J Biacchi
- Nanoscale Device Characterization Division, National Institute of Standards and Technology (NIST), Gaithersburg, Maryland 20899, United States
| | - Hsin Wang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - George S Nolas
- Department of Physics, University of South Florida, Tampa, Florida 33620, United States
| |
Collapse
|
5
|
Li Z, Liu H, Zhao Z, Zhang Q, Fu X, Li X, Gu F, Zhong H, Pan Y, Chen G, Li Q, Li H, Chen Y, Gu L, Jin K, Yan S, Miao GX, Ge C, Li Q. Space-Charge Control of Magnetism in Ferromagnetic Metals: Coupling Giant Magnitude and Robust Endurance. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207353. [PMID: 36479745 DOI: 10.1002/adma.202207353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/24/2022] [Indexed: 06/17/2023]
Abstract
Ferromagnetic metals show great prospects in ultralow-power-consumption spintronic devices, due to their high Curie temperature and robust magnetization. However, there is still a lack of reliable solutions for giant and reversible voltage control of magnetism in ferromagnetic metal films. Here, a novel space-charge approach is proposed which allows for achieving a modulation of 30.3 emu/g under 1.3 V in Co/TiO2 multilayer granular films. The robust endurance with more than 5000 cycles is demonstrated. Similar phenomena exist in Ni/TiO2 and Fe/TiO2 multilayer granular films, which shows its universality. The magnetic change of 107% in Ni/TiO2 underlines its potential in a voltage-driven ON-OFF magnetism. Such giant and reversible voltage control of magnetism can be ascribed to space-charge effect at the ferromagnetic metals/TiO2 interfaces, in which spin-polarized electrons are injected into the ferromagnetic metal layer with the adsorption of lithium-ions on the TiO2 surface. These results open the door for a promising method to modulate the magnetization in ferromagnetic metals, paving the way toward the development of ionic-magnetic-electric coupled applications.
Collapse
Affiliation(s)
- Zhaohui Li
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Hengjun Liu
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Zhiqiang Zhao
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xingke Fu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Xiangkun Li
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Fangchao Gu
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Hai Zhong
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuanyuan Pan
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Guihuan Chen
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Qinghao Li
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Hongsen Li
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
| | - Yanxue Chen
- State Key Laboratory of Crystal Materials, School of Physics, Shandong University, Jinan, 250100, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Kuijuan Jin
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Shishen Yan
- State Key Laboratory of Crystal Materials, School of Physics, Shandong University, Jinan, 250100, China
| | - Guo-Xing Miao
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
- Department of Electrical and Computer Engineering & Institute for Quantum Computing, University of Waterloo, Ontario, N2L 3G1, Canada
| | - Chen Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Qiang Li
- University-Industry Joint Center for Ocean Observation and Broadband Communication, State Key Laboratory of Bio-Fibers and Eco-Textiles, Weihai Innovation Research Institute, College of Materials, College of Physics, Qingdao University, Qingdao, 266071, China
- Department of Electrical and Computer Engineering & Institute for Quantum Computing, University of Waterloo, Ontario, N2L 3G1, Canada
| |
Collapse
|
6
|
Kamada T, Ueda T, Fukuura S, Yumura T, Hosokawa S, Tanaka T, Kan D, Shimakawa Y. Ultralong Distance Hydrogen Spillover Enabled by Valence Changes in a Metal Oxide Surface. J Am Chem Soc 2023; 145:1631-1637. [PMID: 36625846 DOI: 10.1021/jacs.2c09729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hydrogen spillover is a phenomenon in which hydrogen atoms generated on metal catalysts diffuse onto catalyst supports. This phenomenon offers reaction routes for functional materials. However, due to difficulties in visualizing hydrogen, the fundamental nature of the phenomenon, such as how far hydrogen diffuses, has not been well understood. Here, in this study, we fabricated catalytic model systems based on Pd-loaded SrFeOx (x ∼ 2.8) epitaxial films and investigated hydrogen spillover. We show that hydrogen spillover on the SrFeOx support extends over long distances (∼600 μm). Furthermore, the hydrogen-spillover-induced reduction of Fe4+ in the support yields large energies (as large as 200 kJ/mol), leading to the spontaneous hydrogen transfer and driving the surprisingly ultralong hydrogen diffusion. These results show that the valence changes in the supports' surfaces are the primary factor determining the hydrogen spillover distance. Our study leads to a deeper understanding of the long-debated issue of hydrogen spillover and provides insight into designing catalyst systems with enhanced properties.
Collapse
Affiliation(s)
- Taro Kamada
- Institute for Chemical Research, Kyoto University, Uji 611-0011, Kyoto, Japan
| | - Taisei Ueda
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Shuta Fukuura
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Takashi Yumura
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan
| | - Saburo Hosokawa
- Faculty of Materials Science and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Tsunehiro Tanaka
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Daisuke Kan
- Institute for Chemical Research, Kyoto University, Uji 611-0011, Kyoto, Japan.,Elements Strategy Initiative for Catalysts & Batteries (ESICB), Kyoto University, Kyotodaigaku Katsura, Nishikyo-ku, Kyoto 615-8245, Japan
| | - Yuichi Shimakawa
- Institute for Chemical Research, Kyoto University, Uji 611-0011, Kyoto, Japan
| |
Collapse
|
7
|
Wang Q, Gu Y, Chen C, Pan F, Song C. Oxide Spintronics as a Knot of Physics and Chemistry: Recent Progress and Opportunities. J Phys Chem Lett 2022; 13:10065-10075. [PMID: 36264651 DOI: 10.1021/acs.jpclett.2c02634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Transition-metal oxides (TMOs) constitute a key material family in spintronics because of mutually coupled degrees of freedom and tunable magneto-ionic properties. In this Perspective, we consider oxide spintronics as a knot of physics and chemistry and mainly discuss two current hot topics: spin-charge interconversion and magneto-ionics. First, spin-charge interconversion is focused on oxide films and heterostructures including 4d/5d heavy metal oxides (e.g., SrIrO3) and two-dimensional electron gases. Based on spin-charge interconversion, charge currents can be transformed to spin currents and generate spin-orbit torque in oxide/metal and all-oxide heterostructures. Additionally, the voltage control of magnetism in TMOs by the magneto-ionic pathway has rapidly accelerated during the past few years due to the versatile advantages of effective control, nonvolatile nature, low power cost, etc. Typical magneto-ionic oxide systems and corresponding physicochemical mechanisms will be discussed. Finally, further developments of oxide spintronics are envisioned, including material discovery, physics exploration, device design, and manipulation methods.
Collapse
Affiliation(s)
- Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Youdi Gu
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Chong Chen
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Feng Pan
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| | - Cheng Song
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing100084, China
| |
Collapse
|
8
|
Wang X, Mayrhofer L, Keunecke M, Estrade S, Lopez-Conesa L, Moseler M, Waag A, Schaefer L, Shi W, Meng X, Chu J, Fan Z, Shen H. Low-Energy Hydrogen Ions Enable Efficient Room-Temperature and Rapid Plasma Hydrogenation of TiO 2 Nanorods for Enhanced Photoelectrochemical Activity. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2204136. [PMID: 36192163 DOI: 10.1002/smll.202204136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/01/2022] [Indexed: 06/16/2023]
Abstract
Hydrogenation is a promising technique to prepare black TiO2 (H-TiO2 ) for solar water splitting, however, there remain limitations such as severe preparation conditions and underexplored hydrogenation mechanisms to inefficient hydrogenation and poor photoelectrochemical (PEC) performance to be overcome for practical applications. Here, a room-temperature and rapid plasma hydrogenation (RRPH) strategy that realizes low-energy hydrogen ions of below 250 eV to fabricate H-TiO2 nanorods with controllable disordered shell, outperforming incumbent hydrogenations, is reported. The mechanisms of efficient RRPH and enhanced PEC activity are experimentally and theoretically unraveled. It is discovered that low-energy hydrogen ions with fast subsurface transport kinetics and shallow penetration depth features, enable them to directly penetrate TiO2 via unique multiple penetration pathways to form controllable disordered shell and suppress bulk defects, ultimately leading to improved PEC performance. Furthermore, the hydrogenation-property experiments reveal that the enhanced PEC activity is mainly ascribed to increasing band bending and bulk defect suppression, compared to reported H-TiO2 , a superior photocurrent density of 2.55 mA cm-2 at 1.23 VRHE is achieved. These findings demonstrate a sustainable strategy which offers great promise of TiO2 and other oxides to achieve further-improved material properties for broad practical applications.
Collapse
Affiliation(s)
- Xiaodan Wang
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Leonhard Mayrhofer
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108, Freiburg, Germany
| | - Martin Keunecke
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Sonia Estrade
- Department d'Electrònica, Universitat de Barcelona, c/Martí Franquès 1, Barcelona, 08028, Spain
| | - Lluis Lopez-Conesa
- Department d'Electrònica, Universitat de Barcelona, c/Martí Franquès 1, Barcelona, 08028, Spain
| | - Michael Moseler
- Fraunhofer Institute for Mechanics of Materials IWM, Wöhlerstraße 11, 79108, Freiburg, Germany
| | - Andreas Waag
- Institute for Semiconductor Technology, TU Braunschweig, Hans-Sommer-Strasse 66, 38106, Braunschweig, Germany
| | - Lothar Schaefer
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| | - Weidong Shi
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang, 212013, China
| | - Xiangjian Meng
- Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Yu Tian Road 500, Shanghai, 200083, China
| | - Junhao Chu
- Institute of Optoelectronics, Fudan University, Song Hu Road 2005, Shanghai, 200438, China
| | - Zhiyong Fan
- Department of Electronic and Computer Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Hao Shen
- Fraunhofer Institute for Surface Engineering and Thin Films, Bienroder Weg 54E, 38108, Braunschweig, Germany
| |
Collapse
|
9
|
Wang M, Wang Y, Mo Y, Gao Q, Li Y, Zhu J. Novel hollow α-Fe 2O 3 nanofibers with robust performance enabled multi-functional applications. ENVIRONMENTAL RESEARCH 2022; 212:113459. [PMID: 35588778 DOI: 10.1016/j.envres.2022.113459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/02/2022] [Accepted: 05/07/2022] [Indexed: 06/15/2023]
Abstract
The synthetic strategies of achieving low-cost and high-performance nanofibers are of great significance in the field of catalysis and detection. In this work, a series of electrospun α-Fe2O3 nanofibers with hollow structure were prepared via combination technology of electrospinning, hydrothermal synthesis, and controlled calcination process. Especially, the influences of the crystal structure and morphology on the comprehensive properties of nanofibers have been explored in detail. The results indicated that α-Fe2O3 nanofibers could be obtained via the calcination at 600-800 °C. Rice-like α-Fe2O3 particles were observed to assemble a stable exoskeleton, supporting a robust tubular cavity. And this tubular structure turned gradually into groove-like structure as the calcination temperature increased, accompanied by tunable crystallization, specific surface area and magnetic property. Finally, combined with series of validation tests, including dye decolorization, electrochemical detection of trace cadmium ions and Fenton degradation of polyvinyl alcohol, the resultant α-Fe2O3 nanofibers have been demonstrated to show the potential application prospects.
Collapse
Affiliation(s)
- Mingxu Wang
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
| | - Yangyi Wang
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
| | - Yongchun Mo
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China
| | - Qiang Gao
- School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, 225002, China; Fujian Key Laboratory of Novel Functional Textile Fibers and Materials, Minjiang University, Fuzhou, 350108, China.
| | - Yonggui Li
- Fujian Key Laboratory of Novel Functional Textile Fibers and Materials, Minjiang University, Fuzhou, 350108, China.
| | - Jiadeng Zhu
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
| |
Collapse
|
10
|
Wang WH, Pan CY, Liu CM, Lin WC, Jiang PH. Chirality-Induced Noncollinear Magnetization and Asymmetric Domain-Wall Propagation in Hydrogenated CoPd Thin Films. ACS APPLIED MATERIALS & INTERFACES 2022; 14:20151-20158. [PMID: 35468278 DOI: 10.1021/acsami.1c23276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Array-patterned CoPd-based heterostructures are created through e-beam lithography and plasma pretreatment that induces oxidation with depth gradient in the CoPd alloy films, breaking the central symmetry of the structure. Effects on the magnetic properties of the follow-up hydrogenation of the thin film are observed via magneto-optic Kerr effect microscopy. The system exhibits a strong vertical and lateral antiferromagnetic coupling in the perpendicular component between the areas with and without plasma pretreatment, and asymmetric domain-wall propagation in the plasma-pretreated areas during magnetization reversal. These phenomena exhibit evident magnetic chirality and can be interpreted with the Ruderman-Kittel-Kasuya-Yosida coupling and the Dzyaloshinskii-Moriya interaction (DMI). The sample processing demonstrated in this study allows easy incorporation of lithography techniques that can define areas with or without DMI to create intricate magnetic patterns on the sample, which provides an avenue toward more sophisticated control of canted spin textures in future spintronic devices.
Collapse
Affiliation(s)
- Wei-Hsiang Wang
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan
- Department of Physics, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| | - Ching-Yang Pan
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan
| | - Chak-Ming Liu
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan
| | - Wen-Chin Lin
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan
| | - Pei-Hsun Jiang
- Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan
| |
Collapse
|
11
|
Park JK, Jang HM, Cho WJ, Kim C, Suk J, Kim DS, Lee JS. Enhanced anomalous magnetization in carbonyl iron by Ni + ion beam irradiation. Sci Rep 2021; 11:20118. [PMID: 34635765 PMCID: PMC8505505 DOI: 10.1038/s41598-021-99673-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 09/27/2021] [Indexed: 11/09/2022] Open
Abstract
We investigate the magnetic properties in carbonyl iron (CI) particles before and after Ni[Formula: see text] and H[Formula: see text] ion beam irradiation. Upon increasing temperatures, the saturation magnetization ([Formula: see text]) in hysteresis loops exhibits an anomalous increase at a high temperature for the unirradiated and the Ni[Formula: see text]-beam-irradiated samples, unlike in H[Formula: see text]-beam-irradiated sample. Moreover, the magnetization values at low and high temperatures are more intense after Ni[Formula: see text] beam irradiation, whereas after H[Formula: see text] beam irradiation those are remarkably suppressed. Hematite ([Formula: see text]-Fe[Formula: see text]O[Formula: see text]) phase introduced on the surface of our CI particles undergoes the Morin transition that was observed in our magnetization-temperature curves. The Morin transition causing canted antiferromagnetism above the Morin temperature was found in the unirradiated and Ni[Formula: see text]-beam-irradiated samples, but not in H[Formula: see text]-beam-irradiated sample. It is thus revealed that the CI particles undergoing the Morin transition cause the anomalous increase in [Formula: see text]. We may suggest that Ni[Formula: see text] ion beam increases uncompensated surface spins on the CI particles resulting in a more steep Morin transition and the intensified [Formula: see text]. Ion-beam irradiation may thus be a good tool for controlling the magnetic properties of CI particles, tailoring our work for future applications.
Collapse
Affiliation(s)
- Jun Kue Park
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea.
| | - Hye Min Jang
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea
| | - Won-Je Cho
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea.
| | - Chorong Kim
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea
| | - Jaekwon Suk
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea
| | - Dong-Seok Kim
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea
| | - Jae Sang Lee
- Korea Multi-purpose Accelerator Complex, Korea Atomic Energy Research Institute, Gyeongju, 38180, Korea
| |
Collapse
|