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Zheng J, Shi W, Li Z, Zhang J, Yang CY, Zhu Z, Wang M, Zhang J, Han F, Zhang H, Chen Y, Hu F, Shen B, Chen Y, Sun J. Charge-Transfer-Induced Interfacial Ferromagnetism in Ferromagnet-Free Oxide Heterostructures. ACS NANO 2024; 18:9232-9241. [PMID: 38466082 DOI: 10.1021/acsnano.4c01910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Due to the strong interlayer coupling between multiple degrees of freedom, oxide heterostructures have demonstrated exotic properties that are not shown by their bulk counterparts. One of the most interesting properties is ferromagnetism at the interface formed between "nonferromagnetic" compounds. Here we report on the interfacial ferromagnetic phase induced in the superlattices consisting of the two paramagnetic oxides CaRuO3 (CRO) and LaNiO3 (LNO). By varying the sublayer thickness in the superlattice period, we demonstrate that the ferromagnetic order has been established in both CaRuO3 and LaNiO3 sublayers, exhibiting an identical Curie temperature of ∼75 K. The X-ray absorption spectra suggest a strong charge transfer from Ru to Ni at the interface, triggering superexchange interactions between Ru/Ni ions and giving rise to the emergent ferromagnetic phase. Moreover, the X-ray linear dichroism spectra reveal the preferential occupancy of the d3z2-r2 orbital for the Ru ions and the dx2-y2 orbital for the Ni ions in the heterostructure. This leads to different magnetic anisotropy of the superlattices when they are dominated by CRO or LNO sublayers. This work clearly demonstrates a charge-transfer-induced interfacial ferromagnetic phase in the whole ferromagnet-free oxide heterostructures, offering a feasible way to tailor oxide materials for desired functionalities.
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Affiliation(s)
- Jie Zheng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Wenxiao Shi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Zhe Li
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jing Zhang
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, People's Republic of China
| | - Chao-Yao Yang
- Department of Materials Science and Engineering, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Zhaozhao Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Mengqin Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jine Zhang
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
| | - Furong Han
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
| | - Hui Zhang
- School of Integrated Circuit Science and Engineering, Beihang University, Beijing 100191, People's Republic of China
| | - Yunzhong Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Fengxia Hu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, People's Republic of China
| | - Yuansha Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
- School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- Spintronics Institute, School of Physics and Technology, University of Jinan, Jinan 250022, China
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Jilili J, Tolbatov I, Cossu F, Rahaman A, Fiser B, Kahaly MU. Atomic scale interfacial magnetism and origin of metal-insulator transition in (LaNiO[Formula: see text])[Formula: see text]/(CaMnO[Formula: see text])[Formula: see text] superlattices: a first principles study. Sci Rep 2023; 13:5056. [PMID: 36977694 PMCID: PMC10050077 DOI: 10.1038/s41598-023-30686-w] [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: 02/02/2022] [Accepted: 02/28/2023] [Indexed: 03/30/2023] Open
Abstract
Interfacial magnetism and metal-insulator transition at LaNiO[Formula: see text]-based oxide interfaces have triggered intense research efforts, because of the possible implications in future heterostructure device design and engineering. Experimental observation lack in some points a support from an atomistic view. In an effort to fill such gap, we hereby investigate the structural, electronic, and magnetic properties of (LaNiO[Formula: see text])[Formula: see text]/(CaMnO[Formula: see text])[Formula: see text] superlattices with varying LaNiO[Formula: see text] thickness (n) using density functional theory including a Hubbard-type effective on-site Coulomb term. We successfully capture and explain the metal-insulator transition and interfacial magnetic properties, such as magnetic alignments and induced Ni magnetic moments which were recently observed experimentally in nickelate-based heterostructures. In the superlattices modeled in our study, an insulating state is found for n=1 and a metallic character for n=2, 4, with major contribution from Ni and Mn 3d states. The insulating character originates from the disorder effect induced by sudden environment change for the octahedra at the interface, and associated to localized electronic states; on the other hand, for larger n, less localized interfacial states and increased polarity of the LaNiO[Formula: see text] layers contribute to metallicity. We discuss how the interplay between double and super-exchange interaction via complex structural and charge redistributions results in interfacial magnetism. While (LaNiO[Formula: see text])[Formula: see text]/(CaMnO[Formula: see text])[Formula: see text] superlattices are chosen as prototype and for their experimental feasibility, our approach is generally applicable to understand the intricate roles of interfacial states and exchange mechanism between magnetic ions towards the overall response of a magnetic interface or superlattice.
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Affiliation(s)
- J. Jilili
- ELI ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728 Hungary
| | - I. Tolbatov
- Department of Pharmacy, University of Chieti-Pescara “G. d’Annunzio”, Chieti, Italy
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Av. Paisos Catalans 16, 43007 Tarragona, Spain
| | - F. Cossu
- Asia Pacific Center for Theoretical Physics, Pohang, 37673 Korea
- Department of Physics and Institute of Quantum Convergence, Kangwon National University, 24341 Chuncheon, Korea
| | - A. Rahaman
- School of Mechanical Engineering, Vellore Institute of Technology, Vellore, 632014 India
| | - B. Fiser
- Higher Education and Industrial Cooperation Centre, University of Miskolc, Miskolc, 3515 Hungary
- Department of Physical Chemistry, University of Lodz, 90-236 Lodz, Poland
- Ferenc Rakoczi II Transcarpathian Hungarian College of Higher Education, 90200 Beregszász, Ukraine
| | - M. Upadhyay. Kahaly
- ELI ALPS, ELI-HU Non-Profit Ltd., Wolfgang Sandner utca 3., Szeged, H-6728 Hungary
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3
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Gogoi L, Gao W, Ajayan PM, Deb P. Quantum magnetic phenomena in engineered heterointerface of low-dimensional van der Waals and non-van der Waals materials. Phys Chem Chem Phys 2023; 25:1430-1456. [PMID: 36601788 DOI: 10.1039/d2cp05228h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Investigating magnetic phenomena at the microscopic level has emerged as an indispensable research domain in the field of low-dimensional magnetic materials. Understanding quantum phenomena that mediate the magnetic interactions in dimensionally confined materials is crucial from the perspective of designing cheaper, compact, and energy-efficient next-generation spintronic devices. The infrequent occurrence of intrinsic long-range magnetic order in dimensionally confined materials hinders the advancement of this domain. Hence, introducing and controlling the ferromagnetic character in two-dimensional materials is important for further prospective studies. The interface in a heterostructure significantly contributes to modulating its collective magnetic properties. Quantum phenomena occurring at the interface of engineered heterostructures can enhance or suppress magnetization of the system and introduce magnetic character to a native non-magnetic system. Considering most 2D magnetic materials are used as stacks with other materials in nanoscale devices, the methods to control the magnetism in a heterostructure and understanding the corresponding mechanism are crucial for promising spintronic and other functional applications. This review highlights the effect of electric polarization of the adjacent layer, changed structural configuration at the vicinity of the interface, natural strain induced by lattice mismatch, and exchange interaction in the interfacial region in modulating the magnetism of heterostructures of van der Waals and non-van der Waals materials. Further, prospects of interface-engineered magnetism in spin-dependent device applications are also discussed.
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Affiliation(s)
- Liyenda Gogoi
- Advanced Functional Materials Laboratory, Department of Physics, Tezpur University (Central University), Tezpur, 784028, India.
| | - Weibo Gao
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, 637371, Singapore
| | - Pulickel M Ajayan
- Benjamin M. and Mary Greenwood Anderson Professor of Engineering, Department of Materials Science and NanoEngineering, Rice University, 6100 Main Street, Houston, Texas 77005, USA.
| | - Pritam Deb
- Advanced Functional Materials Laboratory, Department of Physics, Tezpur University (Central University), Tezpur, 784028, India.
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Zhou G, Li Z, Dou J, Ji H, Kang P, Shen Y, Wang S, Xu X. The polar and nonpolar interfaces influenced of magnetism in LaMnO 3-based superlattices. RSC Adv 2023; 13:10254-10260. [PMID: 37006349 PMCID: PMC10065140 DOI: 10.1039/d3ra00229b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
The interface of perovskite heterostructures has been shown to exhibit various electronic and magnetic phases such as two-dimensional electron gas, magnetism, superconductivity, and electronic phase separation. These rich phases are expected due to the strong interplay between spin, charge, and orbital degree of freedom at the interface. In this work, the polar and nonpolar interfaces are designed in LaMnO3-based (LMO) superlattices to investigate the difference in magnetic and transport properties. For the polar interface in a LMO/SrMnO3 superlattice, a novel robust ferromagnetism, exchange bias effect, vertical magnetization shift, and metallic behaviors coexist due to the polar catastrophe, which results in a double exchange coupling effect in the interface. For the nonpolar interface in a LMO/LaNiO3 superlattice, only the ferromagnetism and exchange bias effect characteristics exist due to the polar continuous interface. This is attributed to the charge transfer between Mn3+ and Ni3+ ions at the interface. Therefore, transition metal oxides exhibit various novel physical properties due to the strong correlation of d electrons and the polar and nonpolar interfaces. Our observations may provide an approach to further tune the properties using the selected polar and nonpolar oxide interfaces. The interface of perovskite heterostructures has been shown to exhibit various electronic and magnetic phases such as two-dimensional electron gas, magnetism, superconductivity, and electronic phase separation![]()
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Affiliation(s)
- Guowei Zhou
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
| | - Zhilan Li
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Jiarui Dou
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Huihui Ji
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
| | - Penghua Kang
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Yufan Shen
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Siqi Wang
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Xiaohong Xu
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
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5
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Shan W, Luo W. Interfacial charge transfer induced antiferromagnetic metals and magnetic phase transition in (CrO 2) m/(TaO 2) nsuperlattices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 35:035801. [PMID: 36351299 DOI: 10.1088/1361-648x/aca19a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Accepted: 11/09/2022] [Indexed: 06/16/2023]
Abstract
As a class of remarkable spintronic materials, intrinsic antiferromagnetic (AFM) metals are rare. The exploration and investigation of AFM metals are still in its infancy. Based on first-principles calculations, the interface-induced magnetic phenomena in the (CrO2)m/(TaO2)nsuperlattices are investigated, and a new series of AFM metals is predicted. Under different ratios ofm:nwith varying valence states of Cr, the (CrO2)m/(TaO2)nsuperlattices exhibit three different phases, including the AFM metal, the AFM semiconductor, and the ferromagnetic (FM) metal. In the AFM semiconducting phases, theintra-CrO2-monolayer magnetic exchange interaction is systematically discussed, corresponding tom = 1 orm = 2. Both the localization of the Cr 3 dorbitals and the crystal-field splitting are crucial for magnetic ordering in super-exchange interactions. Based on the analyses of the AFM semiconducting phases withm = 1 andm = 2, the mechanisms of AFM metallic phases with radios ofm:n<1/2and1/2<m:n<1/1are discussed in detail. Additionally, the AFM metallic superlattices can be tuned into a FM metallic phase by applying strain in thec-direction, such as a compression of 7% in the (CrO2)1/(TaO2)3superlattice, and a tensile strain of 7% in the (CrO2)2/(TaO2)3superlattice. The phase diagram of the (CrO2)m/(TaO2)nsuperlattices is obtained as a function of the layer thickness. This work provides new insights about realizing and manipulating AFM metals in artificial superlattices or heterostructures in experiments.
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Affiliation(s)
- Wanfei Shan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Weidong Luo
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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6
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De Luca G, Spring J, Kaviani M, Jöhr S, Campanini M, Zakharova A, Guillemard C, Herrero-Martin J, Erni R, Piamonteze C, Rossell MD, Aschauer U, Gibert M. Top-Layer Engineering Reshapes Charge Transfer at Polar Oxide Interfaces. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2203071. [PMID: 35841137 DOI: 10.1002/adma.202203071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 07/12/2022] [Indexed: 06/15/2023]
Abstract
Charge-transfer phenomena at heterointerfaces are a promising pathway to engineer functionalities absent in bulk materials but can also lead to degraded properties in ultrathin films. Mitigating such undesired effects with an interlayer reshapes the interface architecture, restricting its operability. Therefore, developing less-invasive methods to control charge transfer will be beneficial. Here, an appropriate top-interface design allows for remote manipulation of the charge configuration of the buried interface and concurrent restoration of the ferromagnetic trait of the whole film. Double-perovskite insulating ferromagnetic La2 NiMnO6 (LNMO) thin films grown on perovskite oxide substrates are investigated as a model system. An oxygen-vacancy-assisted electronic reconstruction takes place initially at the LNMO polar interfaces. As a result, the magnetic properties of 2-5 unit cell LNMO films are affected beyond dimensionality effects. The introduction of a top electron-acceptor layer redistributes the electron excess and restores the ferromagnetic properties of the ultrathin LNMO films. Such a strategy can be extended to other interfaces and provides an advanced approach to fine-tune the electronic features of complex multilayered heterostructures.
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Affiliation(s)
- Gabriele De Luca
- Department of Physics, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Jonathan Spring
- Department of Physics, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Moloud Kaviani
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, 3012, Switzerland
| | - Simon Jöhr
- Department of Physics, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
| | - Marco Campanini
- Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Anna Zakharova
- Swiss Light Source, Paul Scherrer Institut, Villigen, 5232, Switzerland
| | - Charles Guillemard
- ALBA Synchrotron Light Source, Carrer de la Llum 2-26, Cerdanyola del Vallès, 08290, Spain
| | - Javier Herrero-Martin
- ALBA Synchrotron Light Source, Carrer de la Llum 2-26, Cerdanyola del Vallès, 08290, Spain
| | - Rolf Erni
- Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, 8600, Switzerland
| | | | - Marta D Rossell
- Electron Microscopy Center, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, Dübendorf, 8600, Switzerland
| | - Ulrich Aschauer
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Freiestrasse 3, Bern, 3012, Switzerland
| | - Marta Gibert
- Department of Physics, University of Zurich, Winterthurerstrasse 190, Zurich, 8057, Switzerland
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7
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Shan W, Luo W. Charge transfer and metal-insulator transition in (CrO 2) m/(TaO 2) nsuperlattices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:385001. [PMID: 35835091 DOI: 10.1088/1361-648x/ac8133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/14/2022] [Indexed: 06/15/2023]
Abstract
Various interfacial emergent phenomena have been discovered in tunable nanoscale materials, especially in artificially designed epitaxial superlattices. In conjunction, the atomically fabricated superlattices have exhibited a plethora of exceptional properties compared to either bulk materials separately. Here, the (CrO2)m/(TaO2)nsuperlattices composed of two lattice-matched metallic metal oxides are constructed. With the help of first-principle density-functional theory calculations, a computational and theoretical study of (CrO2)m/(TaO2)nsuperlattices manifests the interfacial electronic properties in detail. The results suggest that emergent properties result from the charge transfer from the TaO2to CrO2layers. At two special ratios of1:1and1:2betweenmandn, the superlattices undergo metal-to-insulator transition. Additionally, the bands below the Fermi level become narrower with the increasing thickness of the CrO2and TaO2layers. The study reveals that the electronic reconstruction at the interface of two metallic materials can generate interesting physics, which points the direction for the manipulation of functionalities in artificial superlattices or heterostructures within a few atomic layers.
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Affiliation(s)
- Wanfei Shan
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Weidong Luo
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
- Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
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8
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Jin Q, Wang Z, Zhang Q, Yu Y, Lin S, Chen S, Qi M, Bai H, Huon A, Li Q, Wang L, Yin X, Tang CS, Wee ATS, Meng F, Zhao J, Wang JO, Guo H, Ge C, Wang C, Yan W, Zhu T, Gu L, Chambers SA, Das S, Charlton T, Fitzsimmons MR, Liu GQ, Wang S, Jin KJ, Yang H, Guo EJ. Room-Temperature Ferromagnetism at an Oxide-Nitride Interface. PHYSICAL REVIEW LETTERS 2022; 128:017202. [PMID: 35061447 DOI: 10.1103/physrevlett.128.017202] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/28/2021] [Accepted: 12/01/2021] [Indexed: 05/28/2023]
Abstract
Heterointerfaces have led to the discovery of novel electronic and magnetic states because of their strongly entangled electronic degrees of freedom. Single-phase chromium compounds always exhibit antiferromagnetism following the prediction of the Goodenough-Kanamori rules. So far, exchange coupling between chromium ions via heteroanions has not been explored and the associated quantum states are unknown. Here, we report the successful epitaxial synthesis and characterization of chromium oxide (Cr_{2}O_{3})-chromium nitride (CrN) superlattices. Room-temperature ferromagnetic spin ordering is achieved at the interfaces between these two antiferromagnets, and the magnitude of the effect decays with increasing layer thickness. First-principles calculations indicate that robust ferromagnetic spin interaction between Cr^{3+} ions via anion-hybridization across the interface yields the lowest total energy. This work opens the door to fundamental understanding of the unexpected and exceptional properties of oxide-nitride interfaces and provides access to hidden phases at low-dimensional quantum heterostructures.
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Affiliation(s)
- Qiao Jin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiwen Wang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Qinghua Zhang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yonghong Yu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shan Lin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shengru Chen
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingqun Qi
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - He Bai
- Spallation Neutron Source Science Center, Dongguan 523803, China
| | - Amanda Huon
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Qian Li
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
| | - Le Wang
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - Xinmao Yin
- Physics Department, Shanghai Key Laboratory of High Temperature Superconductors, Shanghai University, Shanghai 200444, China
| | - Chi Sin Tang
- Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, Singapore 138634, Singapore
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117551, Singapore
| | - Fanqi Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiali Zhao
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jia-Ou Wang
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
| | - Haizhong Guo
- Key Laboratory of Material Physics, Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450001, China
| | - Chen Ge
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Can Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Wensheng Yan
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, China
| | - Tao Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Spallation Neutron Source Science Center, Dongguan 523803, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Lin Gu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Scott A Chambers
- Physical and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354, USA
| | - Sujit Das
- Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, Palaiseau 91767, France
| | - Timothy Charlton
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Michael R Fitzsimmons
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
| | - Gang-Qin Liu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Shanmin Wang
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
| | - Kui-Juan Jin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Hongxin Yang
- Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China
| | - Er-Jia Guo
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
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9
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Mundet B, Domínguez C, Fowlie J, Gibert M, Triscone JM, Alexander DTL. Near-Atomic-Scale Mapping of Electronic Phases in Rare Earth Nickelate Superlattices. NANO LETTERS 2021; 21:2436-2443. [PMID: 33685129 PMCID: PMC7995248 DOI: 10.1021/acs.nanolett.0c04538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/29/2021] [Indexed: 06/12/2023]
Abstract
Nanoscale mapping of the distinct electronic phases characterizing the metal-insulator transition displayed by most of the rare-earth nickelate compounds is fundamental for discovering the true nature of this transition and the possible couplings that are established at the interfaces of nickelate-based heterostructures. Here, we demonstrate that this can be accomplished by using scanning transmission electron microscopy in combination with electron energy-loss spectroscopy. By tracking how the O K and Ni L edge fine structures evolve across two different NdNiO3/SmNiO3 superlattices, displaying either one or two metal-insulator transitions depending on the individual layer thickness, we are able to determine the electronic state of each of the individual constituent materials. We further map the spatial configuration associated with their metallic/insulating regions, reaching unit cell spatial resolution. With this, we estimate the width of the metallic/insulating boundaries at the NdNiO3/SmNiO3 interfaces, which is measured to be on the order of four unit cells.
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Affiliation(s)
- Bernat Mundet
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
- Electron
Spectrometry and Microscopy Laboratory (LSME), Institute of Physics
(IPHYS), École Polytechnique Fédérale
de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Claribel Domínguez
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
| | - Jennifer Fowlie
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
| | - Marta Gibert
- Physik-Institut, University of Zurich, 8057 Zurich, Switzerland
| | - Jean-Marc Triscone
- Department
of Quantum Matter Physics, University of
Geneva, 1211 Geneva, Switzerland
| | - Duncan T. L. Alexander
- Electron
Spectrometry and Microscopy Laboratory (LSME), Institute of Physics
(IPHYS), École Polytechnique Fédérale
de Lausanne (EPFL), 1015 Lausanne, Switzerland
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10
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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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11
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Jiang N, Bai Y, Yang B, Wang D, Zhao S. Switchable metal-insulator transition in core-shell cluster-assembled nanostructure films. NANOSCALE 2020; 12:18144-18152. [PMID: 32852508 DOI: 10.1039/d0nr04681g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Fe/Fe3O4 core-shell-cluster-assembled nanostructured films were prepared using the low-energy cluster beam deposition technique. The temperature-dependent resistivity behaviors were investigated for the films with changing core-occupation ratio of clusters. Much interestingly and surprisingly, a switchable metal-insulator transition can be observed, featuring the rapid switching from the metal state to the insulation state and then back to the metal state, for films within a specific range of core-occupation ratio. Further, the resistivity change rate used to characterize the metal-insulator transition can reach as high as two orders of magnitude over a very narrow temperature region. The design of Fe/Fe3O4 core-shell clusters plays a decisive role in the mechanism of the switchable metal-insulator transition in these films. The assembled core-shell clusters in the films form current conduction channels that are switchable between the cores and shells of clusters as the temperature changes. The switching of the current conduction channels can be regulated by controlling the core-occupation ratios of clusters, which induce a switchable metal-insulator transition and can be verified by the effective medium theory over a specific core-occupation ratio range.
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Affiliation(s)
- Ning Jiang
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, PR China.
| | - Yulong Bai
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, PR China.
| | - Bo Yang
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, PR China.
| | - Dezhi Wang
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, PR China.
| | - Shifeng Zhao
- School of Physical Science and Technology, & Inner Mongolia Key Lab of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021, PR China.
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12
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Cui Z, Grutter AJ, Zhou H, Cao H, Dong Y, Gilbert DA, Wang J, Liu YS, Ma J, Hu Z, Guo J, Xia J, Kirby BJ, Shafer P, Arenholz E, Chen H, Zhai X, Lu Y. Correlation-driven eightfold magnetic anisotropy in a two-dimensional oxide monolayer. SCIENCE ADVANCES 2020; 6:eaay0114. [PMID: 32300646 PMCID: PMC7148107 DOI: 10.1126/sciadv.aay0114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Accepted: 01/13/2020] [Indexed: 05/25/2023]
Abstract
Engineering magnetic anisotropy in two-dimensional systems has enormous scientific and technological implications. The uniaxial anisotropy universally exhibited by two-dimensional magnets has only two stable spin directions, demanding 180° spin switching between states. We demonstrate a previously unobserved eightfold anisotropy in magnetic SrRuO3 monolayers by inducing a spin reorientation in (SrRuO3)1/(SrTiO3) N superlattices, in which the magnetic easy axis of Ru spins is transformed from uniaxial 〈001〉 direction (N < 3) to eightfold 〈111〉 directions (N ≥ 3). This eightfold anisotropy enables 71° and 109° spin switching in SrRuO3 monolayers, analogous to 71° and 109° polarization switching in ferroelectric BiFeO3. First-principle calculations reveal that increasing the SrTiO3 layer thickness induces an emergent correlation-driven orbital ordering, tuning spin-orbit interactions and reorienting the SrRuO3 monolayer easy axis. Our work demonstrates that correlation effects can be exploited to substantially change spin-orbit interactions, stabilizing unprecedented properties in two-dimensional magnets and opening rich opportunities for low-power, multistate device applications.
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Affiliation(s)
- Zhangzhang Cui
- Hefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Alexander J. Grutter
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Hua Zhou
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Hui Cao
- Hefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Yongqi Dong
- Hefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
- Advanced Photon Source, Argonne National Laboratory, Lemont, IL 60439, USA
| | - Dustin A. Gilbert
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA
| | - Jingyuan Wang
- Department of Physics, University of California, Irvine, Irvine, CA 92697, USA
| | - Yi-Sheng Liu
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jiaji Ma
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai 200122, China
| | - Zhenpeng Hu
- School of Physics, Nankai University, Tianjin 300071, China
| | - Jinghua Guo
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jing Xia
- Department of Physics, University of California, Irvine, Irvine, CA 92697, USA
| | - Brian J. Kirby
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Padraic Shafer
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Elke Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY 14853, USA
| | - Hanghui Chen
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai 200122, China
- State Key Laboratory of Precision Spectroscopy, School of Physical and Material Sciences, East China Normal University, Shanghai 200062, China
- Department of Physics, New York University, New York, NY 10027, USA
| | - Xiaofang Zhai
- Hefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Yalin Lu
- Hefei National Laboratory for Physical Sciences at the Microscale, National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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13
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Kharkwal KC, Chaurasia R, Pramanik AK. Unusual exchange bias in Sr 2FeIrO 6/La 0.67Sr 0.33MnO 3 multilayer. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:13LT02. [PMID: 30658343 DOI: 10.1088/1361-648x/ab000a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Here, we study interface induced magnetic properties in a 3d-5d based multilayer made of La0.67Sr0.33MnO3 and double perovskite Sr2FeIrO6, respectively. Bulk La0.67Sr0.33MnO3 is metallic and shows ferromagnetic (FM) ordering above room temperature. In contrast, bulk Sr2FeIrO6, is an antiferromagnet (AFM) with a Néel temperature around 45 K ([Formula: see text]) and exhibits an insulating behavior. Two set of multilayers have been grown on SrTiO3 (1 0 0) crystal with varying thickness of FM layer. A multilayer with equal thickness of La0.67Sr0.33MnO3 and Sr2FeIrO6 (∼10 nm) shows exchange bias (EB) effect both in conventionally field cooled (FC) as well as in zero field cooled (ZFC) magnetic hysteresis measurements which is rather unusual. The ZFC EB effect is weakened both with increasing maximum field during initial magnetization process at low temperature and with increasing temperature. Interestingly, a multilayer with reduced thickness of La0.67Sr0.33MnO3 (∼5 nm) does not exhibit ZFC EB phenomenon, however, the FC EB effect is strengthened showing much higher value. We believe that an AFM type exchange coupling at the interface and its evolution during initial application of magnetic field causes this unusual EB in present multilayers.
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Affiliation(s)
- K C Kharkwal
- School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
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14
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Catalano S, Gibert M, Fowlie J, Íñiguez J, Triscone JM, Kreisel J. Rare-earth nickelates RNiO 3: thin films and heterostructures. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2018; 81:046501. [PMID: 29266004 DOI: 10.1088/1361-6633/aaa37a] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
This review stands in the larger framework of functional materials by focussing on heterostructures of rare-earth nickelates, described by the chemical formula RNiO3 where R is a trivalent rare-earth R = La, Pr, Nd, Sm, …, Lu. Nickelates are characterized by a rich phase diagram of structural and physical properties and serve as a benchmark for the physics of phase transitions in correlated oxides where electron-lattice coupling plays a key role. Much of the recent interest in nickelates concerns heterostructures, that is single layers of thin film, multilayers or superlattices, with the general objective of modulating their physical properties through strain control, confinement or interface effects. We will discuss the extensive studies on nickelate heterostructures as well as outline different approaches to tuning and controlling their physical properties and, finally, review application concepts for future devices.
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Affiliation(s)
- S Catalano
- DQMP, Université de Genève, 24 Quai Ernest-Ansermet, 1211 Geneva, Switzerland
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15
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Guo EJ, Liu Y, Sohn C, Desautels RD, Herklotz A, Liao Z, Nichols J, Freeland JW, Fitzsimmons MR, Lee HN. Oxygen Diode Formed in Nickelate Heterostructures by Chemical Potential Mismatch. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705904. [PMID: 29512212 DOI: 10.1002/adma.201705904] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/25/2017] [Indexed: 06/08/2023]
Abstract
Deliberate control of oxygen vacancy formation and migration in perovskite oxide thin films is important for developing novel electronic and iontronic devices. Here, it is found that the concentration of oxygen vacancies (VO ) formed in LaNiO3 (LNO) during pulsed laser deposition is strongly affected by the chemical potential mismatch between the LNO film and its proximal layers. Increasing the VO concentration in LNO significantly modifies the degree of orbital polarization and drives the metal-insulator transition. Changes in the nickel oxidization state and carrier concentration in the films are confirmed by soft X-ray absorption spectroscopy and optical spectroscopy. The ability to unidirectional-control the oxygen flow across the heterointerface, e.g., a so-called "oxygen diode", by exploiting chemical potential mismatch at interfaces provides a new avenue to tune the physical and electrochemical properties of complex oxides.
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Affiliation(s)
- Er-Jia Guo
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Yaohua Liu
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Changhee Sohn
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Ryan D Desautels
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Andreas Herklotz
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Zhaoliang Liao
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - John Nichols
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - John W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Michael R Fitzsimmons
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - Ho Nyung Lee
- Materials Science and Technology Division and Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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16
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Gong Y, Xu J, Buchanan RC. Surface roughness: A review of its measurement at micro-/nano-scale. PHYSICAL SCIENCES REVIEWS 2018. [DOI: 10.1515/psr-2017-0057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe measurement of surface roughness at micro-/nano-scale is of great importance to metrological, manufacturing, engineering, and scientific applications given the critical roles of roughness in physical and chemical phenomena. The surface roughness of materials can significantly change the way of how they interact with light, phonons, molecules, and so forth, thus surface roughness ultimately determines the functionality and property of materials. In this short review, the techniques of measuring micro-/nano-scale surface roughness are discussed with special focus on the limitations and capabilities of each technique. In addition, the calculations of surface roughness and their theoretical background are discussed to offer readers a better understanding of the importance of post-measurement analysis. Recent progress on fractal analysis of surface roughness is discussed to shed light on the future efforts in surface roughness measurement.
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17
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Yi D, Lu N, Chen X, Shen S, Yu P. Engineering magnetism at functional oxides interfaces: manganites and beyond. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:443004. [PMID: 28745614 DOI: 10.1088/1361-648x/aa824d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The family of transition metal oxides (TMOs) is a large class of magnetic materials that has been intensively studied due to the rich physics involved as well as the promising potential applications in next generation electronic devices. In TMOs, the spin, charge, orbital and lattice are strongly coupled, and significant advances have been achieved to engineer the magnetism by different routes that manipulate these degrees of freedom. The family of manganites is a model system of strongly correlated magnetic TMOs. In this review, using manganites thin films and the heterostructures in conjunction with other TMOs as model systems, we review the recent progress of engineering magnetism in TMOs. We first discuss the role of the lattice that includes the epitaxial strain and the interface structural coupling. Then we look into the role of charge, focusing on the interface charge modulation. Having demonstrated the static effects, we continue to review the research on dynamical control of magnetism by electric field. Next, we review recent advances in heterostructures comprised of high T c cuprate superconductors and manganites. Following that, we discuss the emergent magnetic phenomena at interfaces between 3d TMOs and 5d TMOs with strong spin-orbit coupling. Finally, we provide our outlook for prospective future directions.
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Affiliation(s)
- Di Yi
- Geballe Laboratory for Advanced Materials and Applied Physics Department, Stanford University, Stanford, CA 94305, United States of America
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18
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Magnetic ground state of SrRuO 3 thin film and applicability of standard first-principles approximations to metallic magnetism. Sci Rep 2017; 7:4635. [PMID: 28680121 PMCID: PMC5498660 DOI: 10.1038/s41598-017-04044-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 05/08/2017] [Indexed: 11/20/2022] Open
Abstract
A systematic first-principles study has been performed to understand the magnetism of thin film SrRuO3 which lots of research efforts have been devoted to but no clear consensus has been reached about its ground state properties. The relative t2g level difference, lattice distortion as well as the layer thickness play together in determining the spin order. In particular, it is important to understand the difference between two standard approximations, namely LDA and GGA, in describing this metallic magnetism. Landau free energy analysis and the magnetization-energy-ratio plot clearly show the different tendency of favoring the magnetic moment formation, and it is magnified when applied to the thin film limit where the experimental information is severely limited. As a result, LDA gives a qualitatively different prediction from GGA in the experimentally relevant region of strain whereas both approximations give reasonable results for the bulk phase. We discuss the origin of this difference and the applicability of standard methods to the correlated oxide and the metallic magnetic systems.
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19
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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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20
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Hellman F, Hoffmann A, Tserkovnyak Y, Beach GSD, Fullerton EE, Leighton C, MacDonald AH, Ralph DC, Arena DA, Dürr HA, Fischer P, Grollier J, Heremans JP, Jungwirth T, Kimel AV, Koopmans B, Krivorotov IN, May SJ, Petford-Long AK, Rondinelli JM, Samarth N, Schuller IK, Slavin AN, Stiles MD, Tchernyshyov O, Thiaville A, Zink BL. Interface-Induced Phenomena in Magnetism. REVIEWS OF MODERN PHYSICS 2017; 89:025006. [PMID: 28890576 PMCID: PMC5587142 DOI: 10.1103/revmodphys.89.025006] [Citation(s) in RCA: 181] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This article reviews static and dynamic interfacial effects in magnetism, focusing on interfacially-driven magnetic effects and phenomena associated with spin-orbit coupling and intrinsic symmetry breaking at interfaces. It provides a historical background and literature survey, but focuses on recent progress, identifying the most exciting new scientific results and pointing to promising future research directions. It starts with an introduction and overview of how basic magnetic properties are affected by interfaces, then turns to a discussion of charge and spin transport through and near interfaces and how these can be used to control the properties of the magnetic layer. Important concepts include spin accumulation, spin currents, spin transfer torque, and spin pumping. An overview is provided to the current state of knowledge and existing review literature on interfacial effects such as exchange bias, exchange spring magnets, spin Hall effect, oxide heterostructures, and topological insulators. The article highlights recent discoveries of interface-induced magnetism and non-collinear spin textures, non-linear dynamics including spin torque transfer and magnetization reversal induced by interfaces, and interfacial effects in ultrafast magnetization processes.
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Affiliation(s)
- Frances Hellman
- Department of Physics, University of California, Berkeley, Berkeley, California 94720, USA; Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Axel Hoffmann
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yaroslav Tserkovnyak
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - Geoffrey S D Beach
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Eric E Fullerton
- Center for Memory and Recording Research, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0401, USA
| | - Chris Leighton
- Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Allan H MacDonald
- Department of Physics, University of Texas at Austin, Austin, Texas 78712-0264, USA
| | - Daniel C Ralph
- Physics Department, Cornell University, Ithaca, New York 14853, USA; Kavli Institute at Cornell, Cornell University, Ithaca, New York 14853, USA
| | - Dario A Arena
- Department of Physics, University of South Florida, Tampa, Florida 33620-7100, USA
| | - Hermann A Dürr
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
| | - Peter Fischer
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA; Physics Department, University of California, 1156 High Street, Santa Cruz, California 94056, USA
| | - Julie Grollier
- Unité Mixte de Physique CNRS/Thales and Université Paris Sud 11, 1 Avenue Fresnel, 91767 Palaiseau, France
| | - Joseph P Heremans
- Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210, USA; Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA; Department of Physics, The Ohio State University, Columbus, Ohio 43210, USA
| | - Tomas Jungwirth
- Institute of Physics, Academy of Sciences of the Czech Republic, Cukrovarnicka 10, 162 53 Praha 6, Czech Republic; School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Alexey V Kimel
- Radboud University, Institute for Molecules and Materials, Nijmegen 6525 AJ, The Netherlands
| | - Bert Koopmans
- Department of Applied Physics, Center for NanoMaterials, COBRA Research Institute, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Ilya N Krivorotov
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Steven J May
- Department of Materials Science & Engineering, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Amanda K Petford-Long
- Materials Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439, USA; Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, Illinois 60208, USA
| | - James M Rondinelli
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Nitin Samarth
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Ivan K Schuller
- Department of Physics and Center for Advanced Nanoscience, University of California, San Diego, La Jolla, California 92093, USA; Materials Science and Engineering Program, University of California, San Diego, La Jolla, California 92093, USA
| | - Andrei N Slavin
- Department of Physics, Oakland University, Rochester, Michigan 48309, USA
| | - Mark D Stiles
- Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6202, USA
| | - Oleg Tchernyshyov
- Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, Maryland 21218, USA
| | - André Thiaville
- Laboratoire de Physique des Solides, UMR CNRS 8502, Université Paris-Sud, 91405 Orsay, France
| | - Barry L Zink
- Department of Physics and Astronomy, University of Denver, Denver, CO 80208, USA
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21
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Chen B, Chen P, Xu H, Jin F, Guo Z, Lan D, Wan S, Gao G, Chen F, Wu W. Interfacial Control of Ferromagnetism in Ultrathin La 0.67Ca 0.33MnO 3 Sandwiched between CaRu 1-xTi xO 3 (x = 0-0.8) Epilayers. ACS APPLIED MATERIALS & INTERFACES 2016; 8:34924-34932. [PMID: 27936558 DOI: 10.1021/acsami.6b13158] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Controlling functionalities in oxide heterostructures remains challenging for the rather complex interfacial interactions. Here, by modifying the interface properties with chemical doping, we achieve a nontrivial control over the ferromagnetism in ultrathin La0.67Ca0.33MnO3 (LCMO) layer sandwiched between CaRu1-xTixO3 [CRTO(x)] epilayers. The Ti doping suppresses the interfacial electron transfer from CRTO(x) to LCMO side; as a result, a steadily decreased Curie temperature with increasing x, from 262 K at x = 0 to 186 K at x = 0.8, is observed for the structures with LCMO fixed at 3.2 nm. Moreover, for more insulating CRTO(x ≥ 0.5), the electron confinement induces an interfacial Mn-eg(x2-y2) orbital order in LCMO which further attenuates the ferromagnetism. Also, in order to characterize the heterointerfaces, for the first time the doping- and thickness-dependent metal-insulator transitions in CRTO(x) films are examined. Our results demonstrate that the LCMO/CRTO(x) heterostructure could be a model system for investigating the interfacial multiple interactions in correlated oxides.
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Affiliation(s)
- Binbin Chen
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Pingfan Chen
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Haoran Xu
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Feng Jin
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Zhuang Guo
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Da Lan
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Siyuan Wan
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Guanyin Gao
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
| | - Feng Chen
- High Magnetic Field Laboratory, Chinese Academy of Sciences , Hefei 230031, China
| | - Wenbin Wu
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China , Hefei 230026, China
- High Magnetic Field Laboratory, Chinese Academy of Sciences , Hefei 230031, China
- Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, China
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22
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Grutter AJ, Vailionis A, Borchers JA, Kirby BJ, Flint CL, He C, Arenholz E, Suzuki Y. Interfacial Symmetry Control of Emergent Ferromagnetism at the Nanoscale. NANO LETTERS 2016; 16:5647-5651. [PMID: 27472285 DOI: 10.1021/acs.nanolett.6b02255] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The emergence of complex new ground states at interfaces has been identified as one of the most promising routes to highly tunable nanoscale materials. Despite recent progress, isolating and controlling the underlying mechanisms behind these emergent properties remains among the most challenging materials physics problems to date. In particular, generating ferromagnetism localized at the interface of two nonferromagnetic materials is of fundamental and technological interest. Moreover, the ability to turn the ferromagnetism on and off would shed light on the origin of such emergent phenomena and is promising for spintronic applications. We demonstrate that ferromagnetism confined within one unit cell at the interface of CaRuO3 and CaMnO3 can be switched on and off by changing the symmetry of the oxygen octahedra connectivity at the boundary. Interfaces that are symmetry-matched across the boundary exhibit interfacial CaMnO3 ferromagnetism while the ferromagnetism at symmetry-mismatched interfaces is suppressed. We attribute the suppression of ferromagnetic order to a reduction in charge transfer at symmetry-mismatched interfaces, where frustrated bonding weakens the orbital overlap. Thus, interfacial symmetry is a new route to control emergent ferromagnetism in materials such as CaMnO3 that exhibit antiferromagnetism in bulk form.
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Affiliation(s)
- A J Grutter
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
| | - A Vailionis
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
| | - J A Borchers
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - B J Kirby
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - C L Flint
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
| | - C He
- Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States
| | - E Arenholz
- Advanced Light Source, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Y Suzuki
- Geballe Laboratory for Advanced Materials, Stanford University , Stanford, California 94305, United States
- Department of Applied Physics, Stanford University , Stanford, California 94305, United States
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23
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Emerging magnetism and anomalous Hall effect in iridate-manganite heterostructures. Nat Commun 2016; 7:12721. [PMID: 27596572 PMCID: PMC5025866 DOI: 10.1038/ncomms12721] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 07/27/2016] [Indexed: 11/29/2022] Open
Abstract
Strong Coulomb repulsion and spin–orbit coupling are known to give rise to exotic physical phenomena in transition metal oxides. Initial attempts to investigate systems, where both of these fundamental interactions are comparably strong, such as 3d and 5d complex oxide superlattices, have revealed properties that only slightly differ from the bulk ones of the constituent materials. Here we observe that the interfacial coupling between the 3d antiferromagnetic insulator SrMnO3 and the 5d paramagnetic metal SrIrO3 is enormously strong, yielding an anomalous Hall response as the result of charge transfer driven interfacial ferromagnetism. These findings show that low dimensional spin–orbit entangled 3d–5d interfaces provide an avenue to uncover technologically relevant physical phenomena unattainable in bulk materials. Whilst superlattices containing thin films of 5d transition metal oxides are expected to yield strong interfacial coupling, only weak effects have been observed. Here, the authors report strong coupling between 3d SrMnO3 and 5d SrIrO3 due to the interplay of strong Coulomb and spin orbit interactions.
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24
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Zhang H, Zhang J, Yang H, Lan Q, Hong D, Wang S, Shen X, Khan T, Yu R, Sun J, Shen B. Structural and Magnetic Properties of LaCoO3/SrTiO3 Multilayers. ACS APPLIED MATERIALS & INTERFACES 2016; 8:18328-18333. [PMID: 27377147 DOI: 10.1021/acsami.6b03756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Structural and magnetic properties of the LaCoO3/SrTiO3 (LCO/STO) multilayers (MLs) with a fixed STO layer of 4 nm but varied LCO layer thicknesses have been systematically studied. The MLs grown on Sr0.7La0.3Al0.65Ta0.35O3 (LSAT) and SrTiO3 (STO) exhibit the in-plane lattice constant of the substrates, but those on LaAlO3 (LAO) show the in-plane lattice constant between those of the first two kinds of MLs. Compared with the LCO single layer (SL), the magnetic order of the MLs is significantly enhanced, as demonstrated by a very slow decrease, which is fast for the SL, of the Curie temperature and the saturation magnetization as the LCO layer thickness decreases. For example, clear ferromagnetic order is observed in the ML with the LCO layer of ∼1.5 nm, whereas it vanishes below ∼6 nm for the LCO SL. This result is consistent with the observation that the dark stripes, which are believed to be closely related to the magnetic order, remain clear in the MLs while they are vague in the corresponding LCO SL. The present work suggests a novel route to tune the magnetism of perovskite oxide films.
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Affiliation(s)
- Hongrui Zhang
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Jing Zhang
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Huaiwen Yang
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Qianqian Lan
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Deshun Hong
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Shufang Wang
- College of Physics Science and Technology, Hebei University , Baoding 071002, Hebei Province, People's Republic of China
| | - Xi Shen
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Tahira Khan
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Richeng Yu
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Jirong Sun
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Baogen Shen
- Beijing National Laboratory for Condensed Matter & Institute of Physics, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
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25
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Interlayer coupling through a dimensionality-induced magnetic state. Nat Commun 2016; 7:11227. [PMID: 27079668 PMCID: PMC4835538 DOI: 10.1038/ncomms11227] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 02/25/2016] [Indexed: 11/14/2022] Open
Abstract
Dimensionality is known to play an important role in many compounds for which
ultrathin layers can behave very differently from the bulk. This is especially true
for the paramagnetic metal LaNiO3, which can become insulating and
magnetic when only a few monolayers thick. We show here that an induced
antiferromagnetic order can be stabilized in the [111] direction by
interfacial coupling to the insulating ferromagnet LaMnO3, and used to
generate interlayer magnetic coupling of a nature that depends on the exact number
of LaNiO3 monolayers. For 7-monolayer-thick
LaNiO3/LaMnO3 superlattices, negative and positive
exchange bias, as well as antiferromagnetic interlayer coupling are observed in
different temperature windows. All three behaviours are explained based on the
emergence of a (¼,¼,¼)-wavevector antiferromagnetic structure
in LaNiO3 and the presence of interface asymmetry with LaMnO3.
This dimensionality-induced magnetic order can be used to tailor a broad range of
magnetic properties in well-designed superlattice-based devices. Oxide materials can be combined to create heterostructures exhibiting
complex properties not found in either substance individually. Here, the authors observe
antiferromagnetic interlayer exchange coupling between ferromagnetic lanthanum manganite
and nominally paramagnetic lanthanum nickel oxide.
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26
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Liu Y, Ke X. Interfacial magnetism in complex oxide heterostructures probed by neutrons and x-rays. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:373003. [PMID: 26328474 DOI: 10.1088/0953-8984/27/37/373003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnetic complex-oxide heterostructures are of keen interest because a wealth of phenomena at the interface of dissimilar materials can give rise to fundamentally new physics and potentially valuable functionalities. Altered magnetization, novel magnetic coupling and emergent interfacial magnetism at the epitaxial layered-oxide interfaces are under intensive investigation, which shapes our understanding on how to utilize those materials, particularly for spintronics. Neutron and x-ray based techniques have played a decisive role in characterizing interfacial magnetic structures and clarifying the underlying physics in this rapidly developing field. Here we review some recent experimental results, with an emphasis on those studied via polarized neutron reflectometery and polarized x-ray absorption spectroscopy. We conclude with some perspectives.
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Affiliation(s)
- Yaohua Liu
- Quantum Condensed Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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27
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Jilili J, Cossu F, Schwingenschlögl U. Trends in (LaMnO3)n/(SrTiO3)m superlattices with varying layer thicknesses. Sci Rep 2015; 5:13762. [PMID: 26323361 PMCID: PMC4555181 DOI: 10.1038/srep13762] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 08/04/2015] [Indexed: 11/09/2022] Open
Abstract
We investigate the thickness dependence of the structural, electronic, and magnetic properties of (LaMnO3)n/(SrTiO3)m (n, m = 2, 4, 6, 8) superlattices using density functional theory. The electronic structure turns out to be highly sensitive to the onsite Coulomb interaction. In contrast to bulk SrTiO3, strongly distorted O octahedra are observed in the SrTiO3 layers with a systematic off centering of the Ti atoms. The systems favour ferromagnetic spin ordering rather than the antiferromagnetic spin ordering of bulk LaMnO3 and all show half-metallicity, while a systematic reduction of the minority spin band gaps as a function of the LaMnO3 and SrTiO3 layer thicknesses originates from modifications of the Ti dxy states.
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Affiliation(s)
- J Jilili
- KAUST, PSE Division, Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - F Cossu
- KAUST, PSE Division, Thuwal 23955-6900, Kingdom of Saudi Arabia
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28
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Grutter AJ, Kirby BJ, Gray MT, Flint CL, Alaan US, Suzuki Y, Borchers JA. Electric Field Control of Interfacial Ferromagnetism in CaMnO_{3}/CaRuO_{3} Heterostructures. PHYSICAL REVIEW LETTERS 2015; 115:047601. [PMID: 26252708 DOI: 10.1103/physrevlett.115.047601] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Indexed: 06/04/2023]
Abstract
New mechanisms for achieving direct electric field control of ferromagnetism are highly desirable in the development of functional magnetic interfaces. To that end, we have probed the electric field dependence of the emergent ferromagnetic layer at CaRuO_{3}/CaMnO_{3} interfaces in bilayers fabricated on SrTiO_{3}. Using polarized neutron reflectometry, we are able to detect the ferromagnetic signal arising from a single atomic monolayer of CaMnO_{3}, manifested as a spin asymmetry in the reflectivity. We find that the application of an electric field of 600 kV/m across the bilayer induces a significant increase in this spin asymmetry. Modeling of the reflectivity suggests that this increase corresponds to a transition from canted antiferromagnetism to full ferromagnetic alignment of the Mn^{4+} ions at the interface. This increase from 1 μ_{B} to 2.5-3.0 μ_{B} per Mn is indicative of a strong magnetoelectric coupling effect, and such direct electric field control of the magnetization at an interface has significant potential for spintronic applications.
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Affiliation(s)
- A J Grutter
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - B J Kirby
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - M T Gray
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - C L Flint
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - U S Alaan
- Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
| | - Y Suzuki
- Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, USA
- Department of Applied Physics, Stanford University, Stanford, California 94305, USA
| | - J A Borchers
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
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29
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Pandey P, Das T, Rana R, Parmar JB, Bhattacharyya S, Rana DS. Electronic control of interface ferromagnetic order and exchange-bias in paramagnetic-antiferromagnetic epitaxial bilayers. NANOSCALE 2015; 7:3292-3299. [PMID: 25623888 DOI: 10.1039/c4nr07314b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The hetero-epitaxially engineered magnetic phases, formed due to entanglement of the spin, charge and lattice degrees of freedom, at the atomically sharp interfaces of complex oxide heterostructures are indispensable for devising multifunctional devices. In the quest for novel and superior spintronics functionalities, we have explored the interface magnetism in the epitaxial bilayer of atypical magnetic and electronic states, i.e., of paramagnetic metallic and antiferromagnetic (AFM) insulating phases. In this framework, we observe an unusually strong ferromagnetic order and large exchange-bias fields generated at the interface of the bilayers of metallic CaRuO3 and AFM insulating manganite. The magnetic moment of the interface ferromagnetic order increases linearly with increasing thickness (7-90 nm) of the metallic CaRuO3 layer. This linear scaling signifying an electronic (non-magnetic) control of the interface magnetism and a non-monotonic dependence of the exchange-bias on metallic layers evolve as novel spintronics attributes in atypical bilayers.
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Affiliation(s)
- Parul Pandey
- Department of Physics, Indian Institute of Science Education and Research Bhopal, Govindpura, Bhopal-462023, India.
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30
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Fermi level shifting, charge transfer and induced magnetic coupling at La0.7Ca0.3MnO3/LaNiO3 interface. Sci Rep 2015; 5:8460. [PMID: 25676088 PMCID: PMC4327574 DOI: 10.1038/srep08460] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 01/21/2015] [Indexed: 11/25/2022] Open
Abstract
A large magnetic coupling has been observed at the La0.7Ca0.3MnO3/LaNiO3 (LCMO/LNO) interface. The x-ray photoelectron spectroscopy (XPS) study results show that Fermi level continuously shifted across the LCMO/LNO interface in the interface region. In addition, the charge transfer between Mn and Ni ions of the type Mn3+ − Ni3+ → Mn4+ − Ni2+ with the oxygen vacancies are observed in the interface region. The intrinsic interfacial charge transfer can give rise to itinerant electrons, which results in a “shoulder feature” observed at the low binding energy in the Mn 2p core level spectra. Meanwhile, the orbital reconstruction can be mapped according to the Fermi level position and the charge transfer mode. It can be considered that the ferromagnetic interaction between Ni2+ and Mn4+ gives rise to magnetic regions that pin the ferromagnetic LCMO and cause magnetic coupling at the LCMO/LNO interface.
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31
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Li W, Zhao R, Tang R, Chen A, Zhang W, Lu X, Wang H, Yang H. Vertical-interface-manipulated conduction behavior in nanocomposite oxide thin films. ACS APPLIED MATERIALS & INTERFACES 2014; 6:5356-5361. [PMID: 24689868 DOI: 10.1021/am5001129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Vertically aligned nanocomposites with vertical interfaces are a novel concept that show powerful advantages over conventional nanocomposites with lateral interfaces. However, significant obstacles to a systematic understanding of vertical interfaces still remain. Here, heteroepitaxial (BaTiO3)0.5:(Sm2O3)0.5 nanocomposite thin films have been fabricated and the conduction behaviors have been investigated. A spontaneous phase ordering with clear vertical interfaces has been found in the composite films. Because of the structural discontinuity as well as a large strain generated at the interfaces, the vertical interfaces are revealed to become the sinks to attract oxygen vacancies. The accumulated oxygen vacancies contributed to a largely reduced leakage current and a different leakage mechanism in the composite films compared to that of the pure BaTiO3 film. The present work represents a methodology to manipulate functionalities by designing configuration of the interfaces in oxide thin films.
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Affiliation(s)
- Weiwei Li
- School of Physical Science and Technology & Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou 215006, China
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