1
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Mazza AR, Skoropata E, Sharma Y, Lapano J, Heitmann TW, Musico BL, Keppens V, Gai Z, Freeland JW, Charlton TR, Brahlek M, Moreo A, Dagotto E, Ward TZ. Designing Magnetism in High Entropy Oxides. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200391. [PMID: 35150081 PMCID: PMC8981892 DOI: 10.1002/advs.202200391] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Indexed: 06/14/2023]
Abstract
In magnetic systems, spin and exchange disorder can provide access to quantum criticality, frustration, and spin dynamics, but broad tunability of these responses and a deeper understanding of strong limit disorder are lacking. Here, it is demonstrated that high entropy oxides present a previously unexplored route to designing materials in which the presence of strong local compositional disorder may be exploited to generate tunable magnetic behaviors-from macroscopically ordered states to frustration-driven dynamic spin interactions. Single-crystal La(Cr0.2 Mn0.2 Fe0.2 Co0.2 Ni0.2 )O3 films are used as a model system hosting a magnetic sublattice with a high degree of microstate disorder in the form of site-to-site spin and exchange type inhomogeneity. A classical Heisenberg model simplified to represent the highest probability microstates well describes how compositionally disordered systems can paradoxically host magnetic uniformity and demonstrates a path toward continuous control over ordering types and critical temperatures. Model-predicted materials are synthesized and found to possess an incipient quantum critical point when magnetic ordering types are designed to be in direct competition, this leads to highly controllable exchange bias behaviors previously accessible only in intentionally designed bilayer heterojunctions.
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Affiliation(s)
- Alessandro R. Mazza
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Elizabeth Skoropata
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Yogesh Sharma
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Center for Integrated NanotechnologiesLos Alamos National LaboratoryLos AlamosNM87545USA
| | - Jason Lapano
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Thomas W. Heitmann
- University of Missouri Research ReactorThe University of MissouriColumbiaMO65211USA
| | - Brianna L. Musico
- Department of Materials Science and EngineeringUniversity of TennesseeKnoxvilleTN37996‐4545USA
| | - Veerle Keppens
- Department of Materials Science and EngineeringUniversity of TennesseeKnoxvilleTN37996‐4545USA
| | - Zheng Gai
- Center for Nanophase Materials SciencesOak Ridge National LaboratoryOak RidgeTN37831USA
| | - John W. Freeland
- Advanced Photon SourceArgonne National LaboratoryLemontIL60439USA
| | | | - Matthew Brahlek
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
| | - Adriana Moreo
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of Physics and AstronomyUniversity of TennesseeKnoxvilleTN37996USA
| | - Elbio Dagotto
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
- Department of Physics and AstronomyUniversity of TennesseeKnoxvilleTN37996USA
| | - Thomas Z. Ward
- Materials Science and Technology DivisionOak Ridge National LaboratoryOak RidgeTN37831USA
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2
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Liu C, Liu Y, Zhang B, Sun CJ, Lan D, Chen P, Wu X, Yang P, Yu X, Charlton T, Fitzsimmons MR, Ding J, Chen J, Chow GM. Ferroelectric Self-Polarization Controlled Magnetic Stratification and Magnetic Coupling in Ultrathin La 0.67Sr 0.33MnO 3 Films. ACS APPLIED MATERIALS & INTERFACES 2021; 13:30137-30145. [PMID: 34137601 DOI: 10.1021/acsami.1c02300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Multiferroic oxide heterostructures consisting of ferromagnetic and ferroelectric components hold the promise for nonvolatile magnetic control via ferroelectric polarization, advantageous for the low-dissipation spintronics. Modern understanding of the magnetoelectric coupling in these systems involves structural, orbital, and magnetic reconstructions at interfaces. Previous works have long proposed polarization-dependent interfacial magnetic structures; however, direct evidence is still missing, which requires advanced characterization tools with near-atomic-scale spatial resolutions. Here, extensive polarized neutron reflectometry (PNR) studies have determined the magnetic depth profiles of PbZr0.2Ti0.8O3/La0.67Sr0.33MnO3 (PZT/LSMO) bilayers with opposite self-polarizations. When the LSMO is 2-3 nm thick, the bilayers show two magnetic transitions on cooling. However, temperature-dependent magnetization is different below the lower-temperature transition for opposite polarizations. PNR finds that the LSMO splits into two magnetic sublayers, but the inter-sublayer magnetic couplings are of opposite signs for the two polarizations. Near-edge X-ray absorption spectroscopy further shows contrasts in both the Mn valences and the Mn-O bond anisotropy between the two polarizations. This work completes the puzzle for the magnetoelectric coupling model at the PZT/LSMO interface, showing a synergic interplay among multiple degrees of freedom toward emergent functionalities at complex oxide interfaces.
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Affiliation(s)
- Chao Liu
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Yaohua Liu
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Bangmin Zhang
- School of Physics, Sun Yat-Sen University, Guangzhou510275 Guangdong, China
| | - Cheng-Jun Sun
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Da Lan
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Pingfan Chen
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Xiaohan Wu
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Ping Yang
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore
| | - Timothy Charlton
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Michael R Fitzsimmons
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jun Ding
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Jingsheng Chen
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
| | - Gan Moog Chow
- Department of Materials Science & Engineering, National University of Singapore, Singapore 117575, Singapore
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3
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Xie Z, Cui Z, Shi J, Lin C, Zhang K, Yuan G, Liu JM. Enhancing photoelectrochemical performance of the Bi 2MoO 6 photoanode by ferroelectric polarization regulation. NANOSCALE 2020; 12:18446-18454. [PMID: 32941571 DOI: 10.1039/d0nr02809f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Photoelectrochemical water splitting provides a promising strategy for converting solar energy into chemical fuels and has attracted extensive interest. Herein, Bi2MoO6 nanopillars with large surface areas were fabricated on an ITO-coated glass substrate and their photoelectrochemical properties are enhanced through appropriate manipulation of ferroelectric polarization. The Bi2MoO6 photoanode with polarization orientation toward ITO shows an enhanced photocurrent density of 250 μA cm-2 at 1.23 V vs. reversible hydrogen electrode, which is 28% higher than that of pristine Bi2MoO6 nanopillars without macroscopic polarization. The corresponding depolarization electric field benefits the separation of light-excited electron-hole pairs, thus minimizing the recombination of charge carriers and further enhancing the photocurrent current density. Our work offers a new strategy of Bi2MoO6-based photoelectrochemical devices with great potential of application in the conversion of solar energy into chemical fuels.
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Affiliation(s)
- Zhongshuai Xie
- School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, P. R. China.
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4
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Evolution of ferroelectricity in ultrathin PbTiO 3 films as revealed by electric double layer gating. Sci Rep 2020; 10:10864. [PMID: 32616739 PMCID: PMC7331690 DOI: 10.1038/s41598-020-67580-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 06/10/2020] [Indexed: 11/08/2022] Open
Abstract
Ferroelectricity in ultrathin films is destabilized by depolarization field, which leads to the reduction of spontaneous polarization or domain formation. Here, thickness dependence of remnant polarization in PbTiO3 films is electrically revealed down to 2.6 nm by controlling the polarization direction with employing an electric double layer gating technique to suppress leakage current in ultrathin films. The remnant polarization for a 17 nm-thick film is similar to bulk value ~ 60 μC cm-2 and reduces to ~ 20 μC cm-2 for a 2.6 nm-thick film, whereas robust ferroelectricity is clearly observed in such ultrathin films. In-situ X-ray diffraction measurements under an external electric field reveal that the reduced tetragonality in ultrathin films is mostly recovered by cancelling out the depolarization field. Electric double layer gating technique is an excellent way for exploring physical properties in ultrathin ferroelectric films.
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5
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Fang M, Wang Y, Wang H, Hou Y, Vetter E, Kou Y, Yang W, Yin L, Xiao Z, Li Z, Jiang L, Lee HN, Zhang S, Wu R, Xu X, Sun D, Shen J. Tuning the interfacial spin-orbit coupling with ferroelectricity. Nat Commun 2020; 11:2627. [PMID: 32457302 PMCID: PMC7250895 DOI: 10.1038/s41467-020-16401-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Accepted: 04/28/2020] [Indexed: 11/26/2022] Open
Abstract
Detection and manipulation of spin current lie in the core of spintronics. Here we report an active control of a net spin Hall angle, θSHE(net), in Pt at an interface with a ferroelectric material PZT (PbZr0.2Ti0.8O3), using its ferroelectric polarization. The spin Hall angle in the ultra-thin Pt layer is measured using the inverse spin Hall effect with a pulsed tunneling current from a ferromagnetic La0.67Sr0.33MnO3 electrode. The effect of the ferroelectric polarization on θSHE(net) is enhanced when the thickness of the Pt layer is reduced. When the Pt layer is thinner than 6 nm, switching the ferroelectric polarization even changes the sign of θSHE(net). This is attributed to the reversed polarity of the spin Hall angle in the 1st-layer Pt at the PZT/Pt interface when the ferroelectric polarization is inverted, as supported by the first-principles calculations. These findings suggest a route for designing future energy efficient spin-orbitronic devices using ferroelectric control. The spin Hall angle (SHA) is a measure of the efficiency for converting a charge to a spin current is still challenging to tune in situ. Here, the authors demonstrate by introducing a ferroelectric (FE) material in a ferromagnetic/heavy metal stack the SHA can be voltage controled via the polarization of the FE layer.
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Affiliation(s)
- Mei Fang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 410083, Changsha, Hunan, China
| | - Yanmei Wang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Hui Wang
- Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, 410083, Changsha, Hunan, China.,Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
| | - Yusheng Hou
- Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
| | - Eric Vetter
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA.,Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yunfang Kou
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Wenting Yang
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China
| | - Lifeng Yin
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.,Institute for Nanoelectronics Devices and Quantum Computing, Fudan University, 200433, Shanghai, China.,Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China
| | - Zhu Xiao
- School of Materials Science and Engineering, Central South University, 410083, Changsha, Hunan, China
| | - Zhou Li
- School of Materials Science and Engineering, Central South University, 410083, Changsha, Hunan, China
| | - Lu Jiang
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ho Nyung Lee
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Shufeng Zhang
- Department of Physics, University of Arizona, Tucson, AZ, 85721, USA
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, CA, 92697, USA
| | - Xiaoshan Xu
- Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE, 68588, USA.
| | - Dali Sun
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA. .,Organic and Carbon Electronics Lab (ORaCEL), North Carolina State University, Raleigh, NC, 27695, USA.
| | - Jian Shen
- State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China. .,Institute for Nanoelectronics Devices and Quantum Computing, Fudan University, 200433, Shanghai, China. .,Collaborative Innovation Center of Advanced Microstructures, 210093, Nanjing, China.
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6
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Molinari A, Hahn H, Kruk R. Voltage-Control of Magnetism in All-Solid-State and Solid/Liquid Magnetoelectric Composites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1806662. [PMID: 30785649 DOI: 10.1002/adma.201806662] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 12/20/2018] [Indexed: 06/09/2023]
Abstract
The control of magnetism by means of low-power electric fields, rather than dissipative flowing currents, has the potential to revolutionize conventional methods of data storage and processing, sensing, and actuation. A promising strategy relies on the utilization of magnetoelectric composites to finely tune the interplay between electric and magnetic degrees of freedom at the interface of two functional materials. Albeit early works predominantly focused on the magnetoelectric coupling at solid/solid interfaces; however, recently there has been an increased interest related to the opportunities offered by liquid-gating techniques. Here, a comparative overview on voltage control of magnetism in all-solid-state and solid/liquid composites is presented within the context of the principal coupling mediators, i.e., strain, charge carrier doping, and ionic intercalation. Further, an exhaustive and critical discussion is carried out, concerning the suitability of using the common definition of coupling coefficient α C = Δ M Δ E to compare the strength of the interaction between electricity and magnetism among different magnetoelectric systems.
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Affiliation(s)
- Alan Molinari
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Horst Hahn
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- KIT-TUD-Joint Research Laboratory Nanomaterials, Technical University Darmstadt, Jovanka-Bontschits-Strasse 2, 64287, Darmstadt, Germany
| | - Robert Kruk
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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7
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Gu Y, Xu K, Song C, Zhong X, Zhang H, Mao H, Saleem MS, Sun J, Liu W, Zhang Z, Pan F, Zhu J. Oxygen-Valve Formed in Cobaltite-Based Heterostructures by Ionic Liquid and Ferroelectric Dual-Gating. ACS APPLIED MATERIALS & INTERFACES 2019; 11:19584-19595. [PMID: 31056893 DOI: 10.1021/acsami.9b02442] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Manipulation of oxygen vacancies via electric-field-controlled ionic liquid gating has been reported in many model systems within the emergent fields of oxide electronics and iontronics. It is then significant to investigate the oxygen vacancy formation/annihilation and migration across an additional ferroelectric layer with ionic liquid gating. Here, we report that via a combination of ionic liquid and ferroelectric gating, the remote control of oxygen vacancies and magnetic phase transition can be achieved in SrCoO2.5 films capped with an ultrathin ferroelectric BaTiO3 layer at room temperature. The ultrathin BaTiO3 layer acts as an atomic oxygen valve and is semitransparent to oxygen-ion transport due to the competing interaction between vertical electron tunneling and ferroelectric polarization plus surface electrochemical changes in itself, thus resulting in the striking emergence of new mixed-phase SrCoO x. The lateral coexistence of brownmillerite phase SrCoO2.5 and perovskite phase SrCoO3-δ was directly observed by transmission electron microscopy. Besides the fundamental significance of long-range interaction in ionic liquid gating, the ability to control the flow of oxygen ions across the heterointerface by the oxygen valve provides a new approach on the atomic scale for designing multistate memories, sensors, and solid-oxide fuel cells.
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Affiliation(s)
- Youdi Gu
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shenyang 110016 , China
| | | | | | | | - Hongrui Zhang
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, University of Chinese Academy of Science, Chinese Academy of Sciences , Beijing 100190 , China
| | - Haijun Mao
- College of Aerospace Science and Engineering , National University of Defense Technology , Changsha 410073 , China
| | | | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics , Institute of Physics, University of Chinese Academy of Science, Chinese Academy of Sciences , Beijing 100190 , China
| | - Wei Liu
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shenyang 110016 , China
| | - Zhidong Zhang
- Shenyang National Laboratory for Materials Science , Institute of Metal Research, University of Chinese Academy of Sciences, Chinese Academy of Sciences , Shenyang 110016 , China
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8
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Wang H, Chi X, Liu Z, Yoong H, Tao L, Xiao J, Guo R, Wang J, Dong Z, Yang P, Sun CJ, Li C, Yan X, Wang J, Chow GM, Tsymbal EY, Tian H, Chen J. Atomic-Scale Control of Magnetism at the Titanite-Manganite Interfaces. NANO LETTERS 2019; 19:3057-3065. [PMID: 30964306 DOI: 10.1021/acs.nanolett.9b00441] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Complex oxide thin-film heterostructures often exhibit magnetic properties different from those known for bulk constituents. This is due to the altered local structural and electronic environment at the interfaces, which affects the exchange coupling and magnetic ordering. The emergent magnetism at oxide interfaces can be controlled by ferroelectric polarization and has a strong effect on spin-dependent transport properties of oxide heterostructures, including magnetic and ferroelectric tunnel junctions. Here, using prototype La2/3Sr1/3MnO3/BaTiO3 heterostructures, we demonstrate that ferroelectric polarization of BaTiO3 controls the orbital hybridization and magnetism at heterointerfaces. We observe changes in the enhanced orbital occupancy and significant charge redistribution across the heterointerfaces, affecting the spin and orbital magnetic moments of the interfacial Mn and Ti atoms. Importantly, we find that the exchange coupling between Mn and Ti atoms across the interface is tuned by ferroelectric polarization from ferromagnetic to antiferromagnetic. Our findings provide a viable route to electrically control complex magnetic configurations at artificial multiferroic interfaces, taking a step toward low-power spintronics.
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Affiliation(s)
- Han Wang
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - Xiao Chi
- Department of Physics , National University of Singapore , 2 Science Drive 3 , 117542 Singapore
- Singapore Synchrotron Light Source (SSLS) , National University of Singapore , 117603 Singapore
| | - ZhongRan Liu
- Center of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - HerngYau Yoong
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - LingLing Tao
- Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience , University of Nebraska , Lincoln , Nebraska 68588-0299 , United States
| | - JuanXiu Xiao
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - Rui Guo
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - JingXian Wang
- School of Materials Science and Engineering , Nanyang Technological University , 639798 Singapore
| | - ZhiLi Dong
- School of Materials Science and Engineering , Nanyang Technological University , 639798 Singapore
| | - Ping Yang
- Singapore Synchrotron Light Source (SSLS) , National University of Singapore , 117603 Singapore
| | - Cheng-Jun Sun
- Advanced Photon Source , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - ChangJian Li
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - XiaoBing Yan
- College of Electron and Information Engineering , Hebei University , Baoding 071002 , China
| | - John Wang
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - Gan Moog Chow
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience , University of Nebraska , Lincoln , Nebraska 68588-0299 , United States
| | - He Tian
- Center of Electron Microscope, State Key Laboratory of Silicon Materials, School of Materials Science and Engineering , Zhejiang University , Hangzhou 310027 , China
| | - Jingsheng Chen
- Department of Materials Science and Engineering , National University of Singapore , 117575 Singapore
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9
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Metal-to-Insulator Transition in Ultrathin Manganite Heterostructures. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9010144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Thickness-driven phase transitions have been widely observed in many correlated transition metal oxides materials. One of the important topics is the thickness-driven metal to insulator transition in half-metal La2/3Sr1/3MnO3 (LSMO) thin films, which has attracted great attention in the past few decades. In this article, we review research on the nature of the metal-to-insulator (MIT) transition in LSMO ultrathin films. We discuss in detail the proposed mechanisms, the progress made up to date, and the key issues existing in understanding the related MIT. We also discuss MIT in other correlated oxide materials as a comparison that also has some implications for understanding the origin of MIT.
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10
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Tian Y, Wei L, Zhang Q, Huang H, Zhang Y, Zhou H, Ma F, Gu L, Meng S, Chen LQ, Nan CW, Zhang J. Water printing of ferroelectric polarization. Nat Commun 2018; 9:3809. [PMID: 30228308 PMCID: PMC6143547 DOI: 10.1038/s41467-018-06369-w] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 08/27/2018] [Indexed: 11/08/2022] Open
Abstract
Ferroelectrics, which generate a switchable electric field across the solid-liquid interface, may provide a platform to control chemical reactions (physical properties) using physical fields (chemical stimuli). However, it is challenging to in-situ control such polarization-induced interfacial chemical structure and electric field. Here, we report that construction of chemical bonds at the surface of ferroelectric BiFeO3 in aqueous solution leads to a reversible bulk polarization switching. Combining piezoresponse (electrostatic) force microscopy, X-ray photoelectron spectroscopy, scanning transmission electron microscopy, first-principles calculations and phase-field simulations, we discover that the reversible polarization switching is ascribed to the sufficient formation of polarization-selective chemical bonds at its surface, which decreases the interfacial chemical energy. Therefore, the bulk electrostatic energy can be effectively tuned by H+/OH- concentration. This water-induced ferroelectric switching allows us to construct large-scale type-printing of polarization using green energy and opens up new opportunities for sensing, high-efficient catalysis, and data storage.
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Affiliation(s)
- Yu Tian
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Lanying Wei
- Institute of Physics, Chinese Academy of Science, Beijing National Laboratory of Condensed Matter Physics, Beijing, 100190, China
| | - Qinghua Zhang
- Institute of Physics, Chinese Academy of Science, Beijing National Laboratory of Condensed Matter Physics, Beijing, 100190, China
| | - Houbing Huang
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuelin Zhang
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Hua Zhou
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Fengjie Ma
- Department of Physics, Beijing Normal University, Beijing, 100875, China
| | - Lin Gu
- Institute of Physics, Chinese Academy of Science, Beijing National Laboratory of Condensed Matter Physics, Beijing, 100190, China
| | - Sheng Meng
- Institute of Physics, Chinese Academy of Science, Beijing National Laboratory of Condensed Matter Physics, Beijing, 100190, China
| | - Long-Qing Chen
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, State College, PA, 16802, USA
| | - Ce-Wen Nan
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Jinxing Zhang
- Department of Physics, Beijing Normal University, Beijing, 100875, China.
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11
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Bevan KH, Roy-Gobeil A, Miyahara Y, Grutter P. Relating Franck-Condon blockade to redox chemistry in the single-particle picture. J Chem Phys 2018; 149:104109. [DOI: 10.1063/1.5043480] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Kirk H. Bevan
- Division of Materials Engineering, Faculty of Engineering, McGill University, Montréal, Québec H3A 0C5, Canada
| | - Antoine Roy-Gobeil
- Department of Physics, McGill University, 3600 Rue University, Montréal, Québec H3A 2T8, Canada
| | - Yoichi Miyahara
- Department of Physics, McGill University, 3600 Rue University, Montréal, Québec H3A 2T8, Canada
| | - Peter Grutter
- Department of Physics, McGill University, 3600 Rue University, Montréal, Québec H3A 2T8, Canada
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12
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Wang C, Zhang H, Li C, He Y, Zhang L, Zhao X, Yang Q, Xian D, Mao Q, Peng B, Zhou Z, Cui W, Hu Z. Voltage Control of Magnetic Anisotropy through Ionic Gel Gating for Flexible Spintronics. ACS APPLIED MATERIALS & INTERFACES 2018; 10:29750-29756. [PMID: 30094986 DOI: 10.1021/acsami.8b07469] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In spite of recent rapid development of flexible electronics, voltage-tunable spintronic structures and devices on flexible substrates have been rarely studied. Here, voltage control of magnetic anisotropy (VCMA) is demonstrated via ionic gel (IG) gating on flexible polyimide substrates with a circuit operating voltage of 1.8 V. A reversible, nonvolatile VCMA switching of 114 Oe is achieved in Pt/Fe/Pt multilayer, where the spatial magnetic anisotropy distribution is determined quantitatively by electron spin resonance technique. This IG gating process is repeatable as the substrates are under different bending conditions. The voltage modulation of magnetic anisotropy through IG gating with excellent flexibility proposes potential applications in low-power wearable spintronic devices.
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Affiliation(s)
| | | | | | - Yun He
- National Key Laboratory of Science and Technology on Space Microwave , China Academy of Space Technology , Xi'an 710100 , China
| | | | | | | | | | | | | | | | - Wanzhao Cui
- National Key Laboratory of Science and Technology on Space Microwave , China Academy of Space Technology , Xi'an 710100 , China
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Guo EJ, Charlton T, Ambaye H, Desautels RD, Lee HN, Fitzsimmons MR. Orientation Control of Interfacial Magnetism at La 0.67Sr 0.33MnO 3/SrTiO 3 Interfaces. ACS APPLIED MATERIALS & INTERFACES 2017; 9:19307-19312. [PMID: 28509529 DOI: 10.1021/acsami.7b03252] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Understanding the magnetism at the interface between a ferromagnet and an insulator is essential because the commonly posited magnetic "dead" layer close to an interface can be problematic in magnetic tunnel junctions. Previously, degradation of the magnetic interface was attributed to charge discontinuity across the interface. Here, the interfacial magnetism was investigated using three identically prepared La0.67Sr0.33MnO3 (LSMO) thin films grown on different oriented SrTiO3 (STO) substrates by polarized neutron reflectometry. In all cases the magnetization at the LSMO/STO interface is larger than the film bulk. We show that the interfacial magnetization is largest across the LSMO/STO interfaces with (001) and (111) orientations, which have the largest net charge discontinuities across the interfaces. In contrast, the magnetization of LSMO/STO across the (110) interface, the orientation with no net charge discontinuity, is the smallest of the three orientations. We show that a magnetically degraded interface is not intrinsic to LSMO/STO heterostructures. The approach to use different crystallographic orientations provides a means to investigate the influence of charge discontinuity on the interfacial magnetization.
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Affiliation(s)
- Er-Jia Guo
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Timothy Charlton
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Haile Ambaye
- Instruments and Source Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Ryan D Desautels
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Ho Nyung Lee
- Materials Science and Technology Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Michael R Fitzsimmons
- Quantum Condensed Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
- Department of Physics and Astronomy, University of Tennessee , Knoxville, Tennessee 37996, United States
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