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Shin Y, Poeppelmeier KR, Rondinelli JM. Informatics-Based Learning of Oxygen Vacancy Ordering Principles in Oxygen-Deficient Perovskites. Inorg Chem 2024; 63:12785-12802. [PMID: 38954760 DOI: 10.1021/acs.inorgchem.4c01198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Ordered oxygen vacancies (OOVs) in perovskites can exhibit long-range order and may be used to direct materials properties through modifications in electronic structures and broken symmetries. Based on the various vacancy patterns observed in previously known compounds, we explore the ordering principles of oxygen-deficient perovskite oxides with ABO2.5 stoichiometry to identify other OOV variants. We performed first-principles calculations to assess the OOV stability on a data set of 50 OOV structures generated from our bespoke algorithm. The algorithm employs uniform planar vacancy patterns on (111) pseudocubic perovskite layers and the approach proves effective for generating stable OOV patterns with minimal computational loads. We find as expected that the major factors determining the stability of OOV structures include coordination preferences of transition metals and elastic penalties resulting from the assemblies of polyhedra. Cooperative rotational modes of polyhedra within the OOV structures reduce elastic instabilities by optimizing the bond valence of A- and B cations. This finding explains the observed formation of vacancy channels along low-index crystallographic directions in prototypical OOV phases. The identified ordering principles enable us to devise other stable vacancy patterns with longer periodicity for targeted property design in yet to be synthesized compounds.
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Affiliation(s)
- Yongjin Shin
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Kenneth R Poeppelmeier
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
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2
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Choi S, Son J, MacManus-Driscoll JL, Lee S. Hydrogen-Driven Low-Temperature Topotactic Transition in Nanocomb Cobaltite for Ultralow Power Ionic-Magnetic Coupled Applications. NANO LETTERS 2024; 24:3606-3613. [PMID: 38483316 DOI: 10.1021/acs.nanolett.3c04414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
We reversibly control ferromagnetic-antiferromagnetic ordering in an insulating ground state by annealing tensile-strained LaCoO3 films in hydrogen. This ionic-magnetic coupling occurs due to the hydrogen-driven topotactic transition between perovskite LaCoO3 and brownmillerite La2Co2O5 at a lower temperature (125-200 °C) and within a shorter time (3-10 min) than the oxygen-driven effect (500 °C, tens of hours). The X-ray and optical spectroscopic analyses reveal that the transition results from hydrogen-driven filling of correlated electrons in the Co 3d-orbitals, which successively releases oxygen by destabilizing the CoO6 octahedra into CoO4 tetrahedra. The transition is accelerated by surface exchange, diffusion of hydrogen in and oxygen out through atomically ordered oxygen vacancy "nanocomb" stripes in the tensile-strained LaCoO3 films. Our ionic-magnetic coupling with fast operation, good reproducibility, and long-term stability is a proof-of-principle demonstration of high-performance ultralow power magnetic switching devices for sensors, energy, and artificial intelligence applications, which are keys for attaining carbon neutrality.
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Affiliation(s)
- Songhee Choi
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
| | - Jaeseok Son
- Center for Correlated Electron Systems, Institute for Basic Science, Seoul 08826, Republic of Korea
- Department of Physics and Astronomy, Seoul National University, Seoul 08826, Republic of Korea
| | - Judith L MacManus-Driscoll
- Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Shinbuhm Lee
- Department of Physics and Chemistry, DGIST, Daegu 42988, Republic of Korea
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3
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Zhang R, Su R, Shen C, Xiao R, Cheng W, Miao X. Research Progress on the Application of Topological Phase Transition Materials in the Field of Memristor and Neuromorphic Computing. SENSORS (BASEL, SWITZERLAND) 2023; 23:8838. [PMID: 37960537 PMCID: PMC10650417 DOI: 10.3390/s23218838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/07/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023]
Abstract
Topological phase transition materials have strong coupling between their charge, spin orbitals, and lattice structure, which makes them have good electrical and magnetic properties, leading to promising applications in the fields of memristive devices. The smaller Gibbs free energy difference between the topological phases, the stable oxygen vacancy ordered structure, and the reversible topological phase transition promote the memristive effect, which is more conducive to its application in information storage, information processing, information calculation, and other related fields. In particular, extracting the current resistance or conductance of the two-terminal memristor to convert to the weight of the synapse in the neural network can simulate the behavior of biological synapses in their structure and function. In addition, in order to improve the performance of memristors and better apply them to neuromorphic computing, methods such as ion doping, electrode selection, interface modulation, and preparation process control have been demonstrated in memristors based on topological phase transition materials. At present, it is considered an effective method to obtain a unique resistive switching behavior by improving the process of preparing functional layers, regulating the crystal phase of topological phase transition materials, and constructing interface barrier-dependent devices. In this review, we systematically expound the resistance switching mechanism, resistance switching performance regulation, and neuromorphic computing of topological phase transition memristors, and provide some suggestions for the challenges faced by the development of the next generation of non-volatile memory and brain-like neuromorphic devices based on topological phase transition materials.
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Affiliation(s)
| | | | | | | | - Weiming Cheng
- School of Integrated Circuits, Huazhong University of Science and Technology, Wuhan 430074, China; (R.Z.); (R.S.); (C.S.); (R.X.); (X.M.)
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4
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Yang Z, Wang L, Dhas JA, Engelhard MH, Bowden ME, Liu W, Zhu Z, Wang C, Chambers SA, Sushko PV, Du Y. Guided anisotropic oxygen transport in vacancy ordered oxides. Nat Commun 2023; 14:6068. [PMID: 37770428 PMCID: PMC10539514 DOI: 10.1038/s41467-023-40746-4] [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: 10/26/2022] [Accepted: 08/07/2023] [Indexed: 09/30/2023] Open
Abstract
Anisotropic and efficient transport of ions under external stimuli governs the operation and failure mechanisms of energy-conversion systems and microelectronics devices. However, fundamental understanding of ion hopping processes is impeded by the lack of atomically precise materials and probes that allow for the monitoring and control at the appropriate time- and length- scales. In this work, using in-situ transmission electron microscopy, we directly show that oxygen ion migration in vacancy ordered, semiconducting SrFeO2.5 epitaxial thin films can be guided to proceed through two distinctly different diffusion pathways, each resulting in different polymorphs of SrFeO2.75 with different ground electronic properties before reaching a fully oxidized, metallic SrFeO3 phase. The diffusion steps and reaction intermediates are revealed by means of ab-initio calculations. The principles of controlling oxygen diffusion pathways and reaction intermediates demonstrated here may advance the rational design of structurally ordered oxides for tailored applications and provide insights for developing devices with multiple states of regulation.
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Affiliation(s)
- Zhenzhong Yang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- Key Laboratory of Polar Materials and Devices (MOE), Department of Electronics, East China Normal University, Shanghai, 200241, P. R. China
| | - Le Wang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Jeffrey A Dhas
- School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, 97331, USA
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Mark H Engelhard
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Mark E Bowden
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Wen Liu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430074, China
| | - Zihua Zhu
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Chongmin Wang
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Scott A Chambers
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Peter V Sushko
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
| | - Yingge Du
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA.
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5
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Park TJ, Deng S, Manna S, Islam ANMN, Yu H, Yuan Y, Fong DD, Chubykin AA, Sengupta A, Sankaranarayanan SKRS, Ramanathan S. Complex Oxides for Brain-Inspired Computing: A Review. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203352. [PMID: 35723973 DOI: 10.1002/adma.202203352] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 06/02/2022] [Indexed: 06/15/2023]
Abstract
The fields of brain-inspired computing, robotics, and, more broadly, artificial intelligence (AI) seek to implement knowledge gleaned from the natural world into human-designed electronics and machines. In this review, the opportunities presented by complex oxides, a class of electronic ceramic materials whose properties can be elegantly tuned by doping, electron interactions, and a variety of external stimuli near room temperature, are discussed. The review begins with a discussion of natural intelligence at the elementary level in the nervous system, followed by collective intelligence and learning at the animal colony level mediated by social interactions. An important aspect highlighted is the vast spatial and temporal scales involved in learning and memory. The focus then turns to collective phenomena, such as metal-to-insulator transitions (MITs), ferroelectricity, and related examples, to highlight recent demonstrations of artificial neurons, synapses, and circuits and their learning. First-principles theoretical treatments of the electronic structure, and in situ synchrotron spectroscopy of operating devices are then discussed. The implementation of the experimental characteristics into neural networks and algorithm design is then revewed. Finally, outstanding materials challenges that require a microscopic understanding of the physical mechanisms, which will be essential for advancing the frontiers of neuromorphic computing, are highlighted.
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Affiliation(s)
- Tae Joon Park
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sunbin Deng
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Sukriti Manna
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - A N M Nafiul Islam
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Haoming Yu
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Yifan Yuan
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
| | - Dillon D Fong
- Materials Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Alexander A Chubykin
- Department of Biological Sciences, Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN, 47907, USA
| | - Abhronil Sengupta
- Department of Electrical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Subramanian K R S Sankaranarayanan
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL, 60439, USA
- Department of Mechanical and Industrial Engineering, University of Illinois Chicago, Chicago, IL, 60607, USA
| | - Shriram Ramanathan
- School of Materials Engineering, Purdue University, West Lafayette, IN, 47907, USA
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6
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Bai H, Su X, Zhang Q, Uher C, Tang X, Wu J. Electrically Tunable Antiferroelectric to Paraelectric Switching in a Semiconductor. NANO LETTERS 2022; 22:4083-4089. [PMID: 35549361 DOI: 10.1021/acs.nanolett.2c00787] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The monoclinic α-Cu2Se phase is the first multipolar antiferroelectric semiconductor identified recently by electron microscopy. As a semiconductor, although there are no delocalized electrons to form a static macroscopic polarization, a spontaneous and localized antiferroelectric polarization was found along multiple directions. In conventional ferroelectrics, the polarity can be switched by an applied electric field, and a ferroelectric to paraelectric transition can be modulated by temperature. Here, we show that a reversible and robust antiferroelectric to paraelectric switching in a Cu2Se semiconductor can be tuned electrically by low-voltage and high-frequency electric pulses, and the structural transformations are imaged directly by transmission electron microscopy (TEM). The atomic mechanism of the transformation was assigned to an electrically triggered cation rearrangement with a low-energy barrier. Due to differences of the antiferroelectric and paraelectric phases regarding their electrical, mechanical, and optical properties, such an electrically tunable transformation has a great potential in various applications in microelectronics.
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Affiliation(s)
- Hui Bai
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
- Nanostructure Research Center, Wuhan University of Technology, Wuhan 430070, China
| | - Xianli Su
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Qingjie Zhang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Ctirad Uher
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Xinfeng Tang
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
| | - Jinsong Wu
- State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
- Nanostructure Research Center, Wuhan University of Technology, Wuhan 430070, China
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7
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Tang Y, Chiabrera F, Morata A, Cavallaro A, Liedke MO, Avireddy H, Maller M, Butterling M, Wagner A, Stchakovsky M, Baiutti F, Aguadero A, Tarancón A. Ion Intercalation in Lanthanum Strontium Ferrite for Aqueous Electrochemical Energy Storage Devices. ACS APPLIED MATERIALS & INTERFACES 2022; 14:18486-18497. [PMID: 35412787 DOI: 10.1021/acsami.2c01379] [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
Ion intercalation of perovskite oxides in liquid electrolytes is a very promising method for controlling their functional properties while storing charge, which opens up its potential application in different energy and information technologies. Although the role of defect chemistry in oxygen intercalation in a gaseous environment is well established, the mechanism of ion intercalation in liquid electrolytes at room temperature is poorly understood. In this study, the defect chemistry during ion intercalation of La0.5Sr0.5FeO3-δ thin films in alkaline electrolytes is studied. Oxygen and proton intercalation into the La1-xSrxFeO3-δ perovskite structure is observed at moderate electrochemical potentials (0.5 to -0.4 V), giving rise to a change in the oxidation state of Fe (as a charge compensation mechanism). The variation of the concentration of holes as a function of the intercalation potential is characterized by in situ ellipsometry, and the concentration of electron holes is indirectly quantified for different electrochemical potentials. Finally, a dilute defect chemistry model that describes the variation of defect species during ionic intercalation is developed.
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Affiliation(s)
- Yunqing Tang
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
| | - Francesco Chiabrera
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
- Department of Energy Conversion and Storage, Functional Oxides Group, Technical University of Denmark, Fysikvej 310, 233, 2800 Kongens Lyngby, Denmark
| | - Alex Morata
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
| | - Andrea Cavallaro
- Department of Materials, Imperial College London, London SW7 2AZ, U.K
| | - Maciej O Liedke
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Hemesh Avireddy
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
| | - Mar Maller
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
| | - Maik Butterling
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Andreas Wagner
- Institute of Radiation Physics, Helmholtz-Zentrum Dresden-Rossendorf, 01328 Dresden, Germany
| | - Michel Stchakovsky
- HORIBA Scientific, 14 Boulevard Thomas Gobert, Passage Jobin Yvon, CS 45002-91120 Palaiseau, France
| | - Federico Baiutti
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
- Department of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia
| | - Ainara Aguadero
- Department of Materials, Imperial College London, London SW7 2AZ, U.K
- Instituto de Ciencia de Materiales de Madrid, ICMM-CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid, Spain
| | - Albert Tarancón
- Department of Advanced Materials for Energy Applications, Catalonia Institute for Energy Research (IREC), Jardins de les Dones de Negre 1, 08930 Sant Adrià del Besòs, Barcelona, Spain
- ICREA, Passeig Lluís Companys 23, 08010 Barcelona, Spain
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8
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Puphal P, Wu YM, Fürsich K, Lee H, Pakdaman M, Bruin JAN, Nuss J, Suyolcu YE, van Aken PA, Keimer B, Isobe M, Hepting M. Topotactic transformation of single crystals: From perovskite to infinite-layer nickelates. SCIENCE ADVANCES 2021; 7:eabl8091. [PMID: 34860545 PMCID: PMC8641924 DOI: 10.1126/sciadv.abl8091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Topotactic transformations between related crystal structures are a powerful emerging route for the synthesis of novel quantum materials. Whereas most such “soft chemistry” experiments have been carried out on polycrystalline powders or thin films, the topotactic modification of single crystals, the gold standard for physical property measurements on quantum materials, has been studied only sparsely. Here, we report the topotactic reduction of La1−xCaxNiO3 single crystals to La1−xCaxNiO2+δ using CaH2 as the reducing agent. The transformation from the three-dimensional perovskite to the quasi–two-dimensional infinite-layer phase was thoroughly characterized by x-ray diffraction, electron microscopy, Raman spectroscopy, magnetometry, and electrical transport measurements. Our work demonstrates that the infinite-layer structure can be realized as a bulk phase in crystals with micrometer-sized single domains. The electronic properties of these specimens resemble those of epitaxial thin films rather than powders with similar compositions.
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Affiliation(s)
- Pascal Puphal
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Yu-Mi Wu
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Katrin Fürsich
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Hangoo Lee
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Mohammad Pakdaman
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Jan A N Bruin
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Jürgen Nuss
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Y Eren Suyolcu
- Department of Materials Science and Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Peter A van Aken
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Bernhard Keimer
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Masahiko Isobe
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
| | - Matthias Hepting
- Max Planck Institute for Solid State Research, Heisenbergstraße 1, 70569 Stuttgart, Germany
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9
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Cao L, Petracic O, Wei XK, Zhang H, Duchoň T, Gunkel F, Koutsioubas A, Zhernenkov K, Rushchanskii KZ, Hartmann H, Wilhelm M, Li Z, Xie Y, He S, Weber ML, Veltruská K, Stellhorn A, Mayer J, Zhou S, Brückel T. Migration Kinetics of Surface Ions in Oxygen-Deficient Perovskite During Topotactic Transitions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2104356. [PMID: 34791798 DOI: 10.1002/smll.202104356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/20/2021] [Indexed: 06/13/2023]
Abstract
Oxygen diffusivity and surface exchange kinetics underpin the ionic, electronic, and catalytic functionalities of complex multivalent oxides. Towards understanding and controlling the kinetics of oxygen transport in emerging technologies, it is highly desirable to reveal the underlying lattice dynamics and ionic activities related to oxygen variation. In this study, the evolution of oxygen content is identified in real-time during the progress of a topotactic phase transition in La0.7 Sr0.3 MnO3-δ epitaxial thin films, both at the surface and throughout the bulk. Using polarized neutron reflectometry, a quantitative depth profile of the oxygen content gradient is achieved, which, alongside atomic-resolution scanning transmission electron microscopy, uniquely reveals the formation of a novel structural phase near the surface. Surface-sensitive X-ray spectroscopies further confirm a significant change of the electronic structure accompanying the transition. The anisotropic features of this novel phase enable a distinct oxygen diffusion pathway in contrast to conventional observation of oxygen motion at moderate temperatures. The results provide insights furthering the design of solid oxygen ion conductors within the framework of topotactic phase transitions.
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Affiliation(s)
- Lei Cao
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Oleg Petracic
- Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Xian-Kui Wei
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Hengbo Zhang
- Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Tomáš Duchoň
- Peter Grünberg Institut (PGI-6), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Felix Gunkel
- Peter Grünberg Institut (PGI-7), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Alexandros Koutsioubas
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85748, Garching, Germany
| | - Kirill Zhernenkov
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85748, Garching, Germany
| | - Konstantin Z Rushchanskii
- Peter Grünberg Institute (PGI-1) and Institute for Advanced Simulation (IAS-1), Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Heinrich Hartmann
- Central Institute for Engineering, Electronics and Analytics (ZEA-3), 52425, Jülich, Germany
| | - Marek Wilhelm
- Peter Grünberg Institut (PGI-6), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Zichao Li
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Yufang Xie
- School of Advanced Materials, Peking University, Shenzhen Graduate School, Shenzhen, 518055, China
| | - Suqin He
- Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Peter Grünberg Institut (PGI-7), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Moritz L Weber
- Peter Grünberg Institut (PGI-7), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Kateřina Veltruská
- Department of Surface and Plasma Science, Faculty of Mathematics and Physics, Charles University, Prague, 18000, Czech Republic
| | - Annika Stellhorn
- Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Joachim Mayer
- Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
| | - Shengqiang Zhou
- Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, 01328, Dresden, Germany
| | - Thomas Brückel
- Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, Forschungszentrum Jülich GmbH, 52425, Jülich, Germany
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, 85748, Garching, Germany
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10
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Wang Q, Gu Y, Yin S, Sun Y, Liu W, Zhang Z, Pan F, Song C. Facilitating room-temperature oxygen ion migration via Co-O bond activation in cobaltite films. NANOSCALE 2021; 13:18256-18266. [PMID: 34713881 DOI: 10.1039/d1nr03801j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Oxygen ion migration in strongly correlated oxides can cause dramatic changes in the crystal structure, chemical and magnetoelectric properties, which holds promising for a wide variety of applications in catalysis, energy conversion, and electronics. However, the high strength and stability of metal-oxygen (M-O) bonds cause a large thermodynamic barrier for oxygen migration. Here, we designed Co-O bond activation in cobaltite (SrCoOx) films by Au-nanodot-decoration. Charge transfer from Au to SrCoOx effectively weakens the Co-O bond, meanwhile Co-O-Au synergistic bonding remarkably decreases the migration barrier of oxygen ions. Fast oxygen evolution occurs at the perimeter of the Au/SrCoOx interface, and the chemical potential gradient of O2- drives inner ion diffusion to the surface. Consequently, bias-free topotactic phase reduction from perovskite SrCoO3-δ to brownmillerite SrCoO2.5 has been achieved at room temperature. Our finding explores a new dimension to accelerate oxygen ion kinetics in transition-metal oxides from the aspect of interfacial bond activation, which is significant for developing oxide/noble-metal interfaces for high-efficiency ion migration and redox catalysis at low temperature.
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Affiliation(s)
- Qian Wang
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
| | - Youdi Gu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
| | - Siqi Yin
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
| | - Yiming Sun
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
| | - Wei Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.
| | - Zhidong Zhang
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, 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.
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11
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Salev P, Fratino L, Sasaki D, Berkoun R, Del Valle J, Kalcheim Y, Takamura Y, Rozenberg M, Schuller IK. Transverse barrier formation by electrical triggering of a metal-to-insulator transition. Nat Commun 2021; 12:5499. [PMID: 34535660 PMCID: PMC8448889 DOI: 10.1038/s41467-021-25802-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 08/19/2021] [Indexed: 11/08/2022] Open
Abstract
Application of an electric stimulus to a material with a metal-insulator transition can trigger a large resistance change. Resistive switching from an insulating into a metallic phase, which typically occurs by the formation of a conducting filament parallel to the current flow, is a highly active research topic. Using the magneto-optical Kerr imaging, we found that the opposite type of resistive switching, from a metal into an insulator, occurs in a reciprocal characteristic spatial pattern: the formation of an insulating barrier perpendicular to the driving current. This barrier formation leads to an unusual N-type negative differential resistance in the current-voltage characteristics. We further demonstrate that electrically inducing a transverse barrier enables a unique approach to voltage-controlled magnetism. By triggering the metal-to-insulator resistive switching in a magnetic material, local on/off control of ferromagnetism is achieved using a global voltage bias applied to the whole device.
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Affiliation(s)
- Pavel Salev
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA, USA.
| | - Lorenzo Fratino
- Université Paris-Saclay, CNRS Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Dayne Sasaki
- Department of Materials Science and Engineering, University of California Davis, Davis, CA, USA
| | - Rani Berkoun
- Université Paris-Saclay, CNRS Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Javier Del Valle
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA, USA
- Department of Quantum Matter Physics, University of Geneva, Geneva, Switzerland
| | - Yoav Kalcheim
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA, USA
- Department of Materials Science and Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Yayoi Takamura
- Department of Materials Science and Engineering, University of California Davis, Davis, CA, USA
| | - Marcelo Rozenberg
- Université Paris-Saclay, CNRS Laboratoire de Physique des Solides, 91405, Orsay, France
| | - Ivan K Schuller
- Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, CA, USA
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12
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Mou X, Tang J, Lyu Y, Zhang Q, Yang S, Xu F, Liu W, Xu M, Zhou Y, Sun W, Zhong Y, Gao B, Yu P, Qian H, Wu H. Analog memristive synapse based on topotactic phase transition for high-performance neuromorphic computing and neural network pruning. SCIENCE ADVANCES 2021; 7:7/29/eabh0648. [PMID: 34272239 PMCID: PMC8284889 DOI: 10.1126/sciadv.abh0648] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 06/02/2021] [Indexed: 05/31/2023]
Abstract
Inspired by the human brain, nonvolatile memories (NVMs)-based neuromorphic computing emerges as a promising paradigm to build power-efficient computing hardware for artificial intelligence. However, existing NVMs still suffer from physically imperfect device characteristics. In this work, a topotactic phase transition random-access memory (TPT-RAM) with a unique diffusive nonvolatile dual mode based on SrCoO x is demonstrated. The reversible phase transition of SrCoO x is well controlled by oxygen ion migrations along the highly ordered oxygen vacancy channels, enabling reproducible analog switching characteristics with reduced variability. Combining density functional theory and kinetic Monte Carlo simulations, the orientation-dependent switching mechanism of TPT-RAM is investigated synergistically. Furthermore, the dual-mode TPT-RAM is used to mimic the selective stabilization of developing synapses and implement neural network pruning, reducing ~84.2% of redundant synapses while improving the image classification accuracy to 99%. Our work points out a new direction to design bioplausible memristive synapses for neuromorphic computing.
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Affiliation(s)
- Xing Mou
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Jianshi Tang
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China.
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China
| | - Yingjie Lyu
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Qingtian Zhang
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China
| | - Siyao Yang
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Feng Xu
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Wei Liu
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Minghong Xu
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Yu Zhou
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - Wen Sun
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Yanan Zhong
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
| | - Bin Gao
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China
| | - Pu Yu
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China.
- State Key Laboratory of Low-Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
| | - He Qian
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China
| | - Huaqiang Wu
- School of Integrated Circuits, Beijing National Research Center for Information Science and Technology (BNRist), Tsinghua University, Beijing 100084, China
- Beijing Innovation Center for Future Chips (ICFC), Tsinghua University, Beijing, China
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13
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Xu K, Gu Y, Song C, Zhong X, Zhu J. Atomic insight into spin, charge and lattice modulations at SrFeO 3-x/SrTiO 3 interfaces. NANOSCALE 2021; 13:6066-6075. [PMID: 33616142 DOI: 10.1039/d0nr07697j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Novel phenomena and functionalities at interfaces of oxide heterostructures are currently of great interest in a wide range of applications. At such interfaces, charge, spin, orbital and lattice ordering coexist and correlate closely, contributing to rich functional responses. By using atomically resolved imaging and spectroscopy techniques, we investigated magnetic behaviors and structural modulation at the SrFeO3-x/SrTiO3 interface. Fe/Ti element intermixing and oxygen vacancies occurred across a few unit cells at the interface. Furthermore, antiferromagnetic spin ordering of Fe with different valence states in the interface of SrFeO3-x/SrTiO3 induced uncompensated magnetic moments. Compared to the SrFeO3-x/La0.3Sr0.7Al0.65Ta0.35O3 heterojunction, the variations of charge and lattice order parameters at the SrFeO3-x/SrTiO3 interfaces were also determined by advanced electron microscopy, which provided a good understanding of the physical origin of disparate macroscopic magnetic properties, further investigated by magnetometer measurements and X-ray magnetic circular dichroism (XMCD) spectra. These studies provide comprehensive insight into the interfacial modulation of ferrite oxide, which may be useful for designing future devices in oxide electronics.
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Affiliation(s)
- Kun Xu
- 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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14
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Wang L, Yang Z, Bowden ME, Freeland JW, Sushko PV, Spurgeon SR, Matthews B, Samarakoon WS, Zhou H, Feng Z, Engelhard MH, Du Y, Chambers SA. Hole-Trapping-Induced Stabilization of Ni 4 + in SrNiO 3 /LaFeO 3 Superlattices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2005003. [PMID: 33006412 DOI: 10.1002/adma.202005003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/06/2020] [Indexed: 06/11/2023]
Abstract
Creating new functionality in materials containing transition metals is predicated on the ability to control the associated charge states. For a given transition metal, there is an upper limit on valence that is not exceeded under normal conditions. Here, it is demonstrated that this limit of 3+ for Ni and Fe can be exceeded via synthesis of (SrNiO3 )m /(LaFeO3 )n superlattices by tuning n and m. The Goldschmidt tolerance constraints are lifted, and SrNi4+ O3 with holes on adjacent O anions is stabilized as a perovskite at the single-unit-cell level (m = 1). Holding m = 1, spectroscopy reveals that the n = 1 superlattice contains Ni3+ and Fe4+ , whereas Ni4+ and Fe3+ are observed in the n = 5 superlattice. It is revealed that the B-site cation valences can be tuned by controlling the magnitude of the FeO6 octahedral rotations, which, in turn, determine the energy balance between Ni3+ /Fe4+ and Ni4+ /Fe3+ , thus controlling emergent electrical properties such as the band alignment and resulting hole confinement. This approach can be extended to other systems for synthesizing novel, metastable layered structures with new functionalities.
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Affiliation(s)
- Le Wang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Zhenzhong Yang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Mark E Bowden
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - John W Freeland
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Peter V Sushko
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Steven R Spurgeon
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Bethany Matthews
- Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Widitha S Samarakoon
- School of Chemical, Biological and Environment Engineering, Oregon State University, Corvallis, OR, 97331, USA
| | - Hua Zhou
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Zhenxing Feng
- School of Chemical, Biological and Environment Engineering, Oregon State University, Corvallis, OR, 97331, USA
| | - Mark H Engelhard
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA, 99352, USA
| | - Yingge Du
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
| | - Scott A Chambers
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, 99354, USA
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15
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Lim JS, Lee J, Lee BJ, Kim YJ, Park HS, Suh J, Nahm HH, Kim SW, Cho BG, Koo TY, Choi E, Kim YH, Yang CH. Harnessing the topotactic transition in oxide heterostructures for fast and high-efficiency electrochromic applications. SCIENCE ADVANCES 2020; 6:6/41/eabb8553. [PMID: 33036971 PMCID: PMC7546704 DOI: 10.1126/sciadv.abb8553] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 08/19/2020] [Indexed: 06/11/2023]
Abstract
Mobile oxygen vacancies offer a substantial potential to broaden the range of optical functionalities of complex transition metal oxides due to their high mobility and the interplay with correlated electrons. Here, we report a large electro-absorptive optical variation induced by a topotactic transition via oxygen vacancy fluidic motion in calcium ferrite with large-scale uniformity. The coloration efficiency reaches ~80 cm2 C-1, which means that a 300-nm-thick layer blocks 99% of transmitted visible light by the electrical switching. By tracking the color propagation, oxygen vacancy mobility can be estimated to be 10-8 cm2 s-1 V-1 near 300°C, which is a giant value attained due to the mosaic pseudomonoclinic film stabilized on LaAlO3 substrate. First-principles calculations reveal that the defect density modulation associated with hole charge injection causes a prominent change in electron correlation, resulting in the light absorption modulation. Our findings will pave the pathway for practical topotactic electrochromic applications.
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Affiliation(s)
- Ji Soo Lim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Lattice Defectronics, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jounghee Lee
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Byeoung Ju Lee
- Department of Physics, University of Seoul, Seoul 02504, Republic of Korea
| | - Yong-Jin Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Lattice Defectronics, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Heung-Sik Park
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Lattice Defectronics, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jeonghun Suh
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea
- Center for Lattice Defectronics, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Ho-Hyun Nahm
- Graduate School of Nanoscience and Technology, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Sang-Woo Kim
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Byeong-Gwan Cho
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Tae Yeong Koo
- Pohang Accelerator Laboratory, POSTECH, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Eunjip Choi
- Department of Physics, University of Seoul, Seoul 02504, Republic of Korea
| | - Yong-Hyun Kim
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea.
- Graduate School of Nanoscience and Technology, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Chan-Ho Yang
- Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), Yuseong-gu, Daejeon 34141, Republic of Korea.
- Center for Lattice Defectronics, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
- KAIST Institute for the NanoCentury, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea
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16
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Nallagatla VR, Kim J, Lee K, Chae SC, Hwang CS, Jung CU. Complementary Resistive Switching and Synaptic-Like Memory Behavior in an Epitaxial SrFeO 2.5 Thin Film through Oriented Oxygen-Vacancy Channels. ACS APPLIED MATERIALS & INTERFACES 2020; 12:41740-41748. [PMID: 32799524 DOI: 10.1021/acsami.0c10910] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Oxygen-vacancy-ordered brownmillerite oxides offer a reversible topotactic phase transition by significantly varying the oxygen stoichiometry of the material without losing its lattice framework. This phase transition leads to substantial changes in the physical and chemical properties of brownmillerite oxides, including electrical and ion conductivity, magnetic state, and oxygen diffusivity. In this study, the variations in the resistive switching mode of the epitaxial brownmillerite SrFeO2.5 thin film in the device were studied by systematically controlling the oxygen concentration, which could be varied by changing the compliance current during the first electroforming step. Depending on the compliance current, the SrFeO2.5 devices exhibited either low-power bipolar resistive switching or complementary resistive switching behaviors. A physical model based on the internal redistribution of oxygen ions between the interfaces with the top and the bottom electrodes was developed to explain the complementary resistive switching behavior. This model was experimentally validated using impedance spectroscopy. Finally, the gradual conductance variation in the brownmillerite SrFeO2.5 thin films was exploited to realize synaptic learning.
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Affiliation(s)
- Venkata Raveendra Nallagatla
- Department of Physics and Memory and Catalyst Research Center, Hankuk University of Foreign Studies, Yongin 17035, Korea
| | - Jihun Kim
- Department of Material Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Korea
| | - Kyoungjun Lee
- Department of Physics Education, Seoul National University, Seoul 08826, Korea
| | - Seung Chul Chae
- Department of Physics Education, Seoul National University, Seoul 08826, Korea
| | - Cheol Seong Hwang
- Department of Material Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul 08826, Korea
| | - Chang Uk Jung
- Department of Physics and Memory and Catalyst Research Center, Hankuk University of Foreign Studies, Yongin 17035, Korea
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17
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Lin G, Wang H, Cai X, Tong W, Zhu H. Electroresistance effect in oxygen-deficient La 0.8Ba 0.2MnO 3-δthin films. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:425703. [PMID: 32721929 DOI: 10.1088/1361-648x/aba290] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/03/2020] [Indexed: 06/11/2023]
Abstract
Electroresistance (ER) has been intensively studied in low- and intermediate-bandwidth manganites, which possess phase separation characteristics. As for the Sr- and Ba-doped large-bandwidth manganites, however, few results about ER have been reported so far. Here we report ER effect in oxygen-deficient La0.8Ba0.2MnO3-δthin films, which were obtained by applying a large electric current (33 mA) to the pristine films in vacuum. While the pristine film displays a negligible change in resistivity with respect to the test current, the oxygen-deficient film shows significant ER effect, i.e. ER ratio of -22% at 260 K under a test current of 0.3 mA. By gradually restoring oxygen content in the films, it is found that the ER effect is closely related to the residual resistivity at low temperatures, demonstrating the key role of grain boundaries. Furthermore, the residual resistivity can readily be tuned by heating the oxygen-deficient films in air, suggesting strong oxygen activity in the grain boundaries. The magnetoresistance (MR) data show current dependent feature, also revealing the role of grain boundaries. At 40 K, the MR ratio of the 100 °C restored film under 30 kOe increases from -15% to -25% when decreasing the test current from 1 to 10-3mA. The large ER effect in the oxygen-deficient films is discussed based upon the conductive filament picture in grain boundaries. Our approach to controlling the ER effect through oxygen deficiency makes oxide films more promising for potential applications in the memristive devices and neuomorphic computing.
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Affiliation(s)
- Guankai Lin
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Haoru Wang
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Xuhui Cai
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
| | - Wei Tong
- Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions, High Magnetic Field Laboratory of the Chinese Academy of Sciences, Hefei 230031, People's Republic of China
| | - Hong Zhu
- Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China
- Key Laboratory of Strongly-Coupled Quantum Matter Physics, Chinese Academy of Sciences, No. 96 Jinzhai Road, Hefei, Anhui 230026, People's Republic of China
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18
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Tian J, Zhang Y, Fan Z, Wu H, Zhao L, Rao J, Chen Z, Guo H, Lu X, Zhou G, Pennycook SJ, Gao X, Liu JM. Nanoscale Phase Mixture and Multifield-Induced Topotactic Phase Transformation in SrFeO x. ACS APPLIED MATERIALS & INTERFACES 2020; 12:21883-21893. [PMID: 32314574 DOI: 10.1021/acsami.0c03684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Nanoscale phase mixtures in transition-metal oxides (TMOs) often render these materials susceptible to external stimuli (electric field, mechanical stress, etc.), which can lead to rich functional properties and device applications. Here, direct observation and multifield manipulation of a nanoscale mixture of brownmillerite SrFeO2.5 (BM-SFO) and perovskite SrFeO3 (PV-SFO) phases in SrFeOx (SFO) epitaxial thin films are reported. The mixed-phase SFO film in its pristine state exhibits a nanoscaffold structure consisting of PV-SFO nanodomains embedded in the BM-SFO matrix. This nanoscaffold structure produces gridlike patterns in the current and electrochemical strain maps, owing to the strikingly different electrical and electrochemical properties of BM-SFO and PV-SFO. Moreover, electric field control of reversible topotactic phase transformation between BM-SFO and PV-SFO is demonstrated by electric-field-induced reversible changes in surface height, conductance, and electrochemical strain response. In addition, it is also shown that the BM-SFO → PV-SFO phase transformation can be enabled by applying mechanical stress. This study therefore not only identifies a strong nanometric structure-property correlation in the mixed-phase SFO but also offers a new paradigm for the multifield control of topotactic phase transformation.
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Affiliation(s)
- Junjiang Tian
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Yang Zhang
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
- Instrumental Analysis Center of Xi'an Jiaotong University, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhen Fan
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Haijun Wu
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
| | - Lei Zhao
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Jingjing Rao
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Zuhuang Chen
- School of Materials Science and Engineering, Harbin Institute of Technology, Shenzhen 518055, China
| | - Haizhong Guo
- School of Physical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Xubing Lu
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Guofu Zhou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Xingsen Gao
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
| | - Jun-Ming Liu
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
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19
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Tian J, Wu H, Fan Z, Zhang Y, Pennycook SJ, Zheng D, Tan Z, Guo H, Yu P, Lu X, Zhou G, Gao X, Liu JM. Nanoscale Topotactic Phase Transformation in SrFeO x Epitaxial Thin Films for High-Density Resistive Switching Memory. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1903679. [PMID: 31639262 DOI: 10.1002/adma.201903679] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 10/03/2019] [Indexed: 06/10/2023]
Abstract
Resistive switching (RS) memory has stayed at the forefront of next-generation nonvolatile memory technologies. Recently, a novel class of transition metal oxides (TMOs), which exhibit reversible topotactic phase transformation between insulating brownmillerite (BM) phase and conducting perovskite (PV) phase, has emerged as promising candidate materials for RS memories. Nevertheless, the microscopic mechanism of RS in these TMOs is still unclear. Furthermore, RS devices with simultaneously high density and superior memory performance are yet to be reported. Here, using SrFeOx as a model system, it is directly observed that PV SrFeO3 nanofilaments are formed and extend almost through the BM SrFeO2.5 matrix in the ON state and are ruptured in the OFF state, unambiguously revealing a filamentary RS mechanism. The nanofilaments are ≈10 nm in diameter, enabling to downscale Au/SrFeOx /SrRuO3 RS devices to the 100 nm range for the first time. These nanodevices exhibit good performance including ON/OFF ratio as high as ≈104 , retention time over 105 s, and endurance up to 107 cycles. This study significantly advances the understanding of the RS mechanism in TMOs exhibiting topotactic phase transformation, and it also demonstrates the potential of these materials for use in high-density RS memories.
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Affiliation(s)
- Junjiang Tian
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Haijun Wu
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Zhen Fan
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Yang Zhang
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Stephen J Pennycook
- Department of Materials Science and Engineering, National University of Singapore, Singapore, 117575, Singapore
| | - Dongfeng Zheng
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Zhengwei Tan
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Haizhong Guo
- School of Physical Engineering, Zhengzhou University, Zhengzhou, 450001, China
| | - Pu Yu
- State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing, 100084, China
| | - Xubing Lu
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Guofu Zhou
- Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- National Center for International Research on Green Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Xingsen Gao
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
| | - Jun-Ming Liu
- Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou, 510006, China
- Laboratory of Solid State Microstructures and Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210093, China
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