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Liu ZK. Quantitative predictive theories through integrating quantum, statistical, equilibrium, and nonequilibrium thermodynamics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:343003. [PMID: 38701831 DOI: 10.1088/1361-648x/ad4762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 05/03/2024] [Indexed: 05/05/2024]
Abstract
Today's thermodynamics is largely based on the combined law for equilibrium systems and statistical mechanics derived by Gibbs in 1873 and 1901, respectively, while irreversible thermodynamics for nonequilibrium systems resides essentially on the Onsager Theorem as a separate branch of thermodynamics developed in 1930s. Between them, quantum mechanics was invented and quantitatively solved in terms of density functional theory (DFT) in 1960s. These three scientific domains operate based on different principles and are very much separated from each other. In analogy to the parable of the blind men and the elephant articulated by Perdew, they individually represent different portions of a complex system and thus are incomplete by themselves alone, resulting in the lack of quantitative agreement between their predictions and experimental observations. Over the last two decades, the author's group has developed a multiscale entropy approach (recently termed as zentropy theory) that integrates DFT-based quantum mechanics and Gibbs statistical mechanics and is capable of accurately predicting entropy and free energy of complex systems. Furthermore, in combination with the combined law for nonequilibrium systems presented by Hillert, the author developed the theory of cross phenomena beyond the phenomenological Onsager Theorem. The zentropy theory and theory of cross phenomena jointly provide quantitative predictive theories for systems from electronic to any observable scales as reviewed in the present work.
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Affiliation(s)
- Zi-Kui Liu
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802, United States of America
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2
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Lu X, Liu J, Zhang N, Xie B, Yang S, Liu W, Jiang Z, Huang Z, Yang Y, Miao J, Li W, Cho S, Liu Z, Liu Z, Shen D. Dimensionality-Controlled Evolution of Charge-Transfer Energy in Digital Nickelates Superlattices. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105864. [PMID: 35603969 PMCID: PMC9313943 DOI: 10.1002/advs.202105864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Fundamental understanding and control of the electronic structure evolution in rare-earth nickelates is a fascinating and meaningful issue, as well as being helpful to understand the mechanism of recently discovered superconductivity. Here the dimensionality effect on the ground electronic state in high-quality (NdNiO3 ) m /(SrTiO3 )1 superlattices is systematically studied through transport and soft X-ray absorption spectroscopy. The metal-to-insulator transition temperature decreases with the thickness of the NdNiO3 slab decreasing from bulk to 7 unit cells, then increases gradually as m further reduces to 1 unit cell. Spectral evidence demonstrates that the stabilization of insulating phase can be attributed to the increase of the charge-transfer energy between O 2p and Ni 3d bands. The prominent multiplet feature on the Ni L3 edge develops with the decrease of NdNiO3 slab thickness, suggesting the strengthening of the charge disproportionate state under the dimensional confinement. This work provides convincing evidence that dimensionality is an effective knob to modulate the charge-transfer energy and thus the collective ground state in nickelates.
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Affiliation(s)
- Xiangle Lu
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Jishan Liu
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Nian Zhang
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Binping Xie
- Feimion Instruments (Shanghai) Company LimitedShanghai201906China
| | - Shuai Yang
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Wanling Liu
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zhicheng Jiang
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zhe Huang
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Yichen Yang
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Jin Miao
- State Key Laboratory of Surface PhysicsDepartment of PhysicsFudan UniversityShanghai200433China
| | - Wei Li
- State Key Laboratory of Surface PhysicsDepartment of PhysicsFudan UniversityShanghai200433China
| | - Soohyun Cho
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zhengtai Liu
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Zhonghao Liu
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
| | - Dawei Shen
- State Key Laboratory of Functional Materials for InformaticsShanghai Institute of Microsystem and Information TechnologyChinese Academy of SciencesShanghai200050China
- Center of Materials Science and Optoelectronics EngineeringUniversity of Chinese Academy of SciencesBeijing100049China
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3
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Caputo M, Ristic Z, Dhaka RS, Das T, Wang Z, Matt CE, Plumb NC, Guedes EB, Jandke J, Naamneh M, Zakharova A, Medarde M, Shi M, Patthey L, Mesot J, Piamonteze C, Radović M. Proximity-Induced Novel Ferromagnetism Accompanied with Resolute Metallicity in NdNiO 3 Heterostructure. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101516. [PMID: 34382373 PMCID: PMC8498901 DOI: 10.1002/advs.202101516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Employing X-ray magnetic circular dichroism (XMCD), angle-resolved photoemission spectroscopy (ARPES), and momentum-resolved density fluctuation (MRDF) theory, the magnetic and electronic properties of ultrathin NdNiO3 (NNO) film in proximity to ferromagnetic (FM) La0.67 Sr0.33 MnO3 (LSMO) layer are investigated. The experimental data shows the direct magnetic coupling between the nickelate film and the manganite layer which causes an unusual ferromagnetic (FM) phase in NNO. Moreover, it is shown the metal-insulator transition in the NNO layer, identified by an abrupt suppression of ARPES spectral weight near the Fermi level (EF ), is absent. This observation suggests that the insulating AFM ground state is quenched in proximity to the FM layer. Combining the experimental data (XMCD and AREPS) with the momentum-resolved density fluctuation calculation (MRDF) reveals a direct link between the MIT and the magnetic orders in NNO systems. This work demonstrates that the proximity layer order can be broadly used to modify physical properties and enrich the phase diagram of RENiO3 (RE = rare-earth element).
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Affiliation(s)
- Marco Caputo
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Zoran Ristic
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
- Institute of Condensed Matter PhysicsEcole Polytechnique Fédérale de Lausanne (EPFL)LausanneCH‐1015Switzerland
- Vinca Institute of Nuclear SciencesUniversity of BelgradeP.O.Box 522Belgrade11000Serbia
| | - Rajendra S. Dhaka
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
- Institute of Condensed Matter PhysicsEcole Polytechnique Fédérale de Lausanne (EPFL)LausanneCH‐1015Switzerland
- Department of PhysicsIndian Institute of Technology Delhi, Hauz KhasNew Delhi110016India
| | - Tanmoy Das
- Department of PhysicsIndian Institute of ScienceBangalore560012India
| | - Zhiming Wang
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
- CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingboZhejiang315201China
| | - Christan E. Matt
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Nicholas C. Plumb
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Eduardo B. Guedes
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Jasmin Jandke
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Muntaser Naamneh
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Anna Zakharova
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Marisa Medarde
- Laboratory for Multiscale Materials ExperimentsPaul Scherrer InstitutVilligenCH‐5232Switzerland
| | - Ming Shi
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Luc Patthey
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Joël Mesot
- Paul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Cinthia Piamonteze
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
| | - Milan Radović
- Photon Science DivisionPaul Scherrer InstituteVilligenCH‐5232Switzerland
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Abreu E, Meyers D, Thorsmølle VK, Zhang J, Liu X, Geng K, Chakhalian J, Averitt RD. Nucleation and Growth Bottleneck in the Conductivity Recovery Dynamics of Nickelate Ultrathin Films. NANO LETTERS 2020; 20:7422-7428. [PMID: 32902285 DOI: 10.1021/acs.nanolett.0c02828] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We investigate THz conductivity dynamics in NdNiO3 and EuNiO3 ultrathin films (15 unit cells, u.c., ∼5.7 nm thick) following a photoinduced thermal quench into the metallic state and reveal a clear contrast between first- and second-order dynamics. While in EuNiO3 the conductivity recovers exponentially, in NdNiO3 the recovery is nonexponential and slower than a simple thermal model. Crucially, it is consistent with first-order dynamics and well-described by a 2d Avrami model, with supercooling leading to metastable phase coexistence on the nano- to mesoscopic scale. This novel observation is a fundamentally dynamic manifestation of the first-order character of the insulator-to-metal transition, which the nanoscale thickness of our films and their fast cooling rate enable us to detect. The large transients seen in our films are promising for fast electronic (and magnetic) switching applications.
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Affiliation(s)
- E Abreu
- Institute for Quantum Electronics, Department of Physics, ETH Zurich, 8093 Zurich, Switzerland
| | - D Meyers
- Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078, United States
| | - V K Thorsmølle
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
| | - J Zhang
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - X Liu
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - K Geng
- Department of Physics, Boston University, Boston, Massachusetts 02215, United States
| | - J Chakhalian
- Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854, United States
| | - R D Averitt
- Department of Physics, UC San Diego, La Jolla, California 92093, United States
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5
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Lee S, Lee AT, Georgescu AB, Fabbris G, Han MG, Zhu Y, Freeland JW, Disa AS, Jia Y, Dean MPM, Walker FJ, Ismail-Beigi S, Ahn CH. Strong Orbital Polarization in a Cobaltate-Titanate Oxide Heterostructure. PHYSICAL REVIEW LETTERS 2019; 123:117201. [PMID: 31573260 DOI: 10.1103/physrevlett.123.117201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 06/21/2019] [Indexed: 06/10/2023]
Abstract
Through a combination of experimental measurements and theoretical modeling, we describe a strongly orbital-polarized insulating ground state in an (LaTiO_{3})_{2}/(LaCoO_{3})_{2} oxide heterostructure. X-ray absorption spectra and ab initio calculations show that an electron is transferred from the titanate to the cobaltate layers. The charge transfer, accompanied by a large octahedral distortion, induces a substantial orbital polarization in the cobaltate layer of a size unattainable via epitaxial strain alone. The asymmetry between in-plane and out-of-plane orbital occupancies in the high-spin cobaltate layer is predicted by theory and observed through x-ray linear dichroism experiments. Manipulating orbital configurations using interfacial coupling within heterostructures promises exciting ground-state engineering for realizing new emergent electronic phases in metal oxide superlattices.
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Affiliation(s)
- Sangjae Lee
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Alex Taekyung Lee
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Alexandru B Georgescu
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
| | - Gilberto Fabbris
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Myung-Geun Han
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Yimei Zhu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - John W Freeland
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Ankit S Disa
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Yichen Jia
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Mark P M Dean
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Frederick J Walker
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Sohrab Ismail-Beigi
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
| | - Charles H Ahn
- Department of Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520, USA
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6
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Abstract
Single crystals of PrNiO3 were grown under an oxygen pressure of 295 bar using a unique high-pressure optical-image floating zone furnace. The crystals, with volume in excess of 1 mm3, were characterized structurally using single crystal and powder X-ray diffraction. Resistivity, specific heat, and magnetic susceptibility were measured, all of which evidenced an abrupt, first order metal-insulator transition (MIT) at ~130 K, in agreement with previous literature reports on polycrystalline specimens. Temperature-dependent single crystal diffraction was performed to investigate changes through the MIT. Our study demonstrates the opportunity space for high fugacity, reactive environments for single crystal growth specifically of perovskite nickelates but more generally to correlated electron oxides.
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7
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Paul A, Mukherjee A, Dasgupta I, Paramekanti A, Saha-Dasgupta T. Hybridization-Switching Induced Mott Transition in ABO_{3} Perovskites. PHYSICAL REVIEW LETTERS 2019; 122:016404. [PMID: 31012727 DOI: 10.1103/physrevlett.122.016404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Revised: 05/20/2018] [Indexed: 06/09/2023]
Abstract
We propose the concept of a "hybridization-switching induced Mott transition" which is relevant to a broad class of ABO_{3} perovskite materials including BiNiO_{3} and PbCrO_{3} that feature extended 6s orbitals on the A-site cation (Bi or Pb), and a strong A-O covalency induced ligand hole. Using ab initio electronic structure and slave rotor theory calculations, we show that such systems exhibit a breathing phonon driven A-site to oxygen hybridization-wave instability which conspires with strong correlations on the B-site transition metal ion (Ni or Cr) to trigger a Mott insulating state. This class of systems is shown to undergo a pressure induced insulator to metal transition accompanied by a colossal volume collapse due to ligand hybridization switching.
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Affiliation(s)
- Atanu Paul
- Department of Solid State Physics, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | - Anamitra Mukherjee
- School of Physical Sciences, National Institute of Science Education and Research, HBNI, Jatni 752050, India
| | - Indra Dasgupta
- Department of Solid State Physics, Indian Association for the Cultivation of Science, Kolkata 700 032, India
| | - Arun Paramekanti
- Department of Physics, University of Toronto, Toronto, Ontario, Canada M5S 1A7
| | - Tanusri Saha-Dasgupta
- Department of Condensed Matter Physics and Materials Science, S.N. Bose National Centre for Basic Sciences, Kolkata 700098, India
- Center for Mathematical, Computational and Data Science, Indian Association for the Cultivation of Science, Kolkata 700 032, India
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8
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Nature of the metal-insulator transition in few-unit-cell-thick LaNiO 3 films. Nat Commun 2018; 9:2206. [PMID: 29880888 PMCID: PMC5992201 DOI: 10.1038/s41467-018-04546-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 05/08/2018] [Indexed: 11/09/2022] Open
Abstract
The nature of the metal-insulator transition in thin films and superlattices of LaNiO3 only a few unit cells in thickness remains elusive despite tremendous effort. Quantum confinement and epitaxial strain have been evoked as the mechanisms, although other factors such as growth-induced disorder, cation non-stoichiometry, oxygen vacancies, and substrate-film interface quality may also affect the observable properties of ultrathin films. Here we report results obtained for near-ideal LaNiO3 films with different thicknesses and terminations grown by atomic layer-by-layer laser molecular beam epitaxy on LaAlO3 substrates. We find that the room-temperature metallic behavior persists until the film thickness is reduced to an unprecedentedly small 1.5 unit cells (NiO2 termination). Electronic structure measurements using X-ray absorption spectroscopy and first-principles calculation suggest that oxygen vacancies existing in the films also contribute to the metal-insulator transition.
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9
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Malashevich A, Marshall MSJ, Visani C, Disa AS, Xu H, Walker FJ, Ahn CH, Ismail-Beigi S. Controlling Mobility in Perovskite Oxides by Ferroelectric Modulation of Atomic-Scale Interface Structure. NANO LETTERS 2018; 18:573-578. [PMID: 29251937 DOI: 10.1021/acs.nanolett.7b04715] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Coherent and epitaxial interfaces permit the realization of electric field driven devices controlled by atomic-scale structural and electronic effects at interfaces. Compared to conventional field effect devices where channel conductivity is modulated by carrier density modification, the propagation of atomic-scale distortions across an interface can control the atomic scale bonding, interatomic electron tunneling rates and thus the mobility of the channel material. We use first-principles theory to design an atomically abrupt epitaxial perovskite heterostructure involving an oxide ferroelectric (PbZr0.2Ti0.8O3) and conducting oxide channel (LaNiO3) where coupling of polar atomic motions to structural distortions can induce large, reversible changes in the channel mobility. We fabricate and characterize the heterostructure and measure record values, larger than 1000%, for the conductivity modulation. Our results describe how purely interfacial effects can be engineered to deliver unique electronic device properties and large responses to external fields.
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Affiliation(s)
- Andrei Malashevich
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
| | - Matthew S J Marshall
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
| | - Cristina Visani
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
| | - Ankit S Disa
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
| | - Haichao Xu
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
- Advanced Materials Laboratory, Fudan University , Shanghai 200433, People's Republic of China
| | - Frederick J Walker
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
| | - Charles H Ahn
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
- Department of Mechanical Engineering and Materials Science, Yale University , New Haven, Connecticut 06520, United States
- Department of Physics, Yale University , New Haven, Connecticut 06520, United States
| | - Sohrab Ismail-Beigi
- Center for Research on Interface Structures and Phenomena (CRISP), Yale University , New Haven, Connecticut 06520, United States
- Department of Applied Physics, Yale University , New Haven, Connecticut 06520, United States
- Department of Mechanical Engineering and Materials Science, Yale University , New Haven, Connecticut 06520, United States
- Department of Physics, Yale University , New Haven, Connecticut 06520, United States
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10
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Shamblin J, Heres M, Zhou H, Sangoro J, Lang M, Neuefeind J, Alonso JA, Johnston S. Experimental evidence for bipolaron condensation as a mechanism for the metal-insulator transition in rare-earth nickelates. Nat Commun 2018; 9:86. [PMID: 29311661 PMCID: PMC5758760 DOI: 10.1038/s41467-017-02561-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 12/08/2017] [Indexed: 11/08/2022] Open
Abstract
Many-body effects produce deviations from the predictions of conventional band theory in quantum materials, leading to strongly correlated phases with insulating or bad metallic behavior. One example is the rare-earth nickelates RNiO3, which undergo metal-to-insulator transitions (MITs) whose origin is debated. Here, we combine total neutron scattering and broadband dielectric spectroscopy experiments to study and compare carrier dynamics and local crystal structure in LaNiO3 and NdNiO3. We find that the local crystal structure of both materials is distorted in the metallic phase, with slow, thermally activated carrier dynamics at high temperature. We further observe a sharp change in conductivity across the MIT in NdNiO3, accompanied by slight differences in the carrier hopping time. These results suggest that changes in carrier concentration drive the MIT through a polaronic mechanism, where the (bi)polaron liquid freezes into the insulating phase across the MIT temperature.
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Affiliation(s)
- Jacob Shamblin
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA
- Department of Nuclear Engineering, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Maximilian Heres
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Haidong Zhou
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Joshua Sangoro
- Department of Chemical and Biomolecular Engineering, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Maik Lang
- Department of Nuclear Engineering, The University of Tennessee, Knoxville, TN, 37996, USA
| | - Joerg Neuefeind
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - J A Alonso
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, E-28049, Madrid, Spain
| | - Steven Johnston
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, TN, 37996, USA.
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11
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Ghosh S, Borisevich AY, Pantelides ST. Engineering an Insulating Ferroelectric Superlattice with a Tunable Band Gap from Metallic Components. PHYSICAL REVIEW LETTERS 2017; 119:177603. [PMID: 29219470 DOI: 10.1103/physrevlett.119.177603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Indexed: 06/07/2023]
Abstract
The recent discovery of "polar metals" with ferroelectriclike displacements offers the promise of designing ferroelectrics with tunable energy gaps by inducing controlled metal-insulator transitions. Here we employ first-principles calculations to design a metallic polar superlattice from nonpolar metal components and show that controlled intermixing can lead to a true insulating ferroelectric with a tunable band gap. We consider a 2/2 superlattice made of two centrosymmetric metallic oxides, La_{0.75}Sr_{0.25}MnO_{3} and LaNiO_{3}, and show that ferroelectriclike displacements are induced. The ferroelectriclike distortion is found to be strongly dependent on the carrier concentration (Sr content). Further, we show that a metal-to-insulator (MI) transition is feasible in this system via disproportionation of the Ni sites. Such a disproportionation and, hence, a MI transition can be driven by intermixing of transition metal ions between Mn and Ni layers. As a result, the energy gap of the resulting ferroelectric can be tuned by varying the degree of intermixing in the experimental fabrication method.
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Affiliation(s)
- Saurabh Ghosh
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Albina Y Borisevich
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Sokrates T Pantelides
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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12
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Palina N, Wang L, Dash S, Yu X, Breese MBH, Wang J, Rusydi A. Investigation of the metal-insulator transition in NdNiO 3 films by site-selective X-ray absorption spectroscopy. NANOSCALE 2017; 9:6094-6102. [PMID: 28447095 DOI: 10.1039/c7nr00742f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this work, multifunctional oxide NdNiO3 (NNO) thin films grown on a SrTiO3 (STO) substrate using pulsed-laser deposition are studied. Temperature dependent resistivity measurements revealed that NNO/STO samples exhibit a sharp thickness dependent metal-insulator transition (MIT) over a range of 150-200 K. It is known that the electronic properties of correlated oxides are extremely complex and sensitive to changes in orbital occupancy. To evaluate the changes in the electronic and/or crystallographic structure responsible for the MIT, a site-selective (O, Ni and Nd) X-ray absorption near edge structure (XANES) analysis is performed above and below the transition temperature. Analysis of XANES spectra suggests that: (i) in NNO films nominally trivalent Ni ions exhibit multiple valency (bond disproportionation), (ii) intermetallic hybridization plays an important role, (iii) the presence of strong O 2p-O 2p hole correlation at low temperature results in the opening of the p-p gap and (iv) the valency of Nd ions matches well with that of Nd3+. For NNO films exhibiting a sharp MIT, Ni 3d electron localization and concurrent existence of Ni 3d8 and Ni 3d8L[combining low line]2 states are responsible for the observed transition. At temperatures below the MIT the O 2p-O 2p hole correlation is strong enough to split the O 2p band stabilizing insulating phase. Temperature and thickness dependent differences observed in the site-selective XANES data are discussed in terms of possible mechanisms for the MIT (negative charge-transfer type).
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Affiliation(s)
- Natalia Palina
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore. and NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore
| | - Le Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Sibashisa Dash
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore. and School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore and Department of Applied Physics, Waseda University, Shinjuku, Tokyo 169-8555, Japan
| | - Xiaojiang Yu
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore.
| | - Mark B H Breese
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore. and Department of Physics, National University of Singapore, Singapore 117542, Singapore
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Andrivo Rusydi
- Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603, Singapore. and NUSNNI-Nanocore, National University of Singapore, Singapore 117411, Singapore and Department of Physics, National University of Singapore, Singapore 117542, Singapore
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13
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Torriss B, Margot J, Chaker M. Metal-Insulator Transition of strained SmNiO 3 Thin Films: Structural, Electrical and Optical Properties. Sci Rep 2017; 7:40915. [PMID: 28098240 PMCID: PMC5241880 DOI: 10.1038/srep40915] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/12/2016] [Indexed: 11/09/2022] Open
Abstract
Samarium nickelate (SmNiO3) thin films were successfully synthesized on LaAlO3 and SrTiO3 substrates using pulsed-laser deposition. The Mott metal-insulator (MI) transition of the thin films is sensitive to epitaxial strain and strain relaxation. Once the strain changes from compressive to tensile, the transition temperature of the SmNiO3 samples shifts to slightly higher values. The optical conductivity reveals the strong dependence of the Drude spectral weight on the strain relaxation. Actually, compressive strain broadens the bandwidth. In contrast, tensile strain causes the effective number of free carriers to reduce which is consistent with the d-band narrowing.
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Affiliation(s)
- B Torriss
- INRS-EMT, 1650 Lionel-Boulet, C. P. 1020, Varennes Québec, J3X 1S2, Canada
| | - J Margot
- Département de Physique, Université de Montréal, CP. 6128 Succ. Centre-ville, Montréal, Québec H3C 3J7, Canada
| | - M Chaker
- INRS-EMT, 1650 Lionel-Boulet, C. P. 1020, Varennes Québec, J3X 1S2, Canada
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14
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Bisogni V, Catalano S, Green RJ, Gibert M, Scherwitzl R, Huang Y, Strocov VN, Zubko P, Balandeh S, Triscone JM, Sawatzky G, Schmitt T. Ground-state oxygen holes and the metal-insulator transition in the negative charge-transfer rare-earth nickelates. Nat Commun 2016; 7:13017. [PMID: 27725665 PMCID: PMC5062575 DOI: 10.1038/ncomms13017] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 08/25/2016] [Indexed: 11/13/2022] Open
Abstract
The metal–insulator transition and the intriguing physical properties of rare-earth perovskite nickelates have attracted considerable attention in recent years. Nonetheless, a complete understanding of these materials remains elusive. Here we combine X-ray absorption and resonant inelastic X-ray scattering (RIXS) spectroscopies to resolve important aspects of the complex electronic structure of rare-earth nickelates, taking NdNiO3 thin film as representative example. The unusual coexistence of bound and continuum excitations observed in the RIXS spectra provides strong evidence for abundant oxygen holes in the ground state of these materials. Using cluster calculations and Anderson impurity model interpretation, we show that distinct spectral signatures arise from a Ni 3d8 configuration along with holes in the oxygen 2p valence band, confirming suggestions that these materials do not obey a conventional positive charge-transfer picture, but instead exhibit a negative charge-transfer energy in line with recent models interpreting the metal–insulator transition in terms of bond disproportionation. Rare-earth perovskite nickelates show intriguing metal–insulator transitions, whose mechanism remains elusive. Here, Bisogni et al. evidenced a 3d8 Ni configuration together with abundance of oxygen 2p holes in the ground state of a NdNiO3 thin film, suggesting a negative charge-transfer scenario.
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Affiliation(s)
- Valentina Bisogni
- Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Sara Catalano
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Robert J Green
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.,Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Marta Gibert
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Raoul Scherwitzl
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Yaobo Huang
- Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland.,Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Vladimir N Strocov
- Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Pavlo Zubko
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.,London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, 17-19 Gordon Street, London WC1H 0HA, UK
| | - Shadi Balandeh
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Jean-Marc Triscone
- Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - George Sawatzky
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1.,Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Thorsten Schmitt
- Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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15
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Plumb NC, Gawryluk DJ, Wang Y, Ristić Z, Park J, Lv BQ, Wang Z, Matt CE, Xu N, Shang T, Conder K, Mesot J, Johnston S, Shi M, Radović M. Momentum-Resolved Electronic Structure of the High-T_{c} Superconductor Parent Compound BaBiO_{3}. PHYSICAL REVIEW LETTERS 2016; 117:037002. [PMID: 27472130 DOI: 10.1103/physrevlett.117.037002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Indexed: 05/12/2023]
Abstract
We investigate the band structure of BaBiO_{3}, an insulating parent compound of doped high-T_{c} superconductors, using in situ angle-resolved photoemission spectroscopy on thin films. The data compare favorably overall with density functional theory calculations within the local density approximation, demonstrating that electron correlations are weak. The bands exhibit Brillouin zone folding consistent with known BiO_{6} breathing distortions. Though the distortions are often thought to coincide with Bi^{3+}/Bi^{5+} charge ordering, core level spectra show that bismuth is monovalent. We further demonstrate that the bands closest to the Fermi level are primarily oxygen derived, while the bismuth 6s states mostly contribute to dispersive bands at deeper binding energy. The results support a model of Bi-O charge transfer in which hole pairs are localized on combinations of the O 2p orbitals.
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Affiliation(s)
- N C Plumb
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - D J Gawryluk
- Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Y Wang
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200, USA
| | - Z Ristić
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J Park
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - B Q Lv
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Z Wang
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Department of Quantum Matter Physics, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - C E Matt
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - N Xu
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - T Shang
- Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - K Conder
- Laboratory for Scientific Developments and Novel Materials, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - J Mesot
- Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
- Laboratory for Solid State Physics, ETH Zürich, CH-8093 Zürich, Switzerland
| | - S Johnston
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996-1200, USA
| | - M Shi
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M Radović
- Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
- SwissFEL, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
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16
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Pure electronic metal-insulator transition at the interface of complex oxides. Sci Rep 2016; 6:27934. [PMID: 27324948 PMCID: PMC4914986 DOI: 10.1038/srep27934] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/24/2016] [Indexed: 11/24/2022] Open
Abstract
In complex materials observed electronic phases and transitions between them often involve coupling between many degrees of freedom whose entanglement convolutes understanding of the instigating mechanism. Metal-insulator transitions are one such problem where coupling to the structural, orbital, charge, and magnetic order parameters frequently obscures the underlying physics. Here, we demonstrate a way to unravel this conundrum by heterostructuring a prototypical multi-ordered complex oxide NdNiO3 in ultra thin geometry, which preserves the metal-to-insulator transition and bulk-like magnetic order parameter, but entirely suppresses the symmetry lowering and long-range charge order parameter. These findings illustrate the utility of heterointerfaces as a powerful method for removing competing order parameters to gain greater insight into the nature of the transition, here revealing that the magnetic order generates the transition independently, leading to an exceptionally rare purely electronic metal-insulator transition with no symmetry change.
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17
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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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18
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Wang L, Ju S, You L, Qi Y, Guo YW, Ren P, Zhou Y, Wang J. Competition between strain and dimensionality effects on the electronic phase transitions in NdNiO3 films. Sci Rep 2015; 5:18707. [PMID: 26687924 PMCID: PMC4685315 DOI: 10.1038/srep18707] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 11/23/2015] [Indexed: 11/08/2022] Open
Abstract
Transition metal oxides host an array of exotic electronic phases, including superconductivity, ferroelectricity, quantum spin liquid and Mott insulators. Their extreme sensitivity to external stimuli enables various routes to manipulate the ground state, which greatly improves our understanding of the physics involved. Here, we report the competition between strain and dimensionality effects on the phase evolution in high quality NdNiO3 films down to several unit cells. While both compressive and tensile strains increase the Ni 3d band width and favor the metallic phase, reducing dimensionality, on the other hand, decreases the covalent band width and favors the insulating phase in NdNiO3. The experimental observations are well supported by ab initio calculations and improve our understanding of the electronic behavior in strongly correlated electron systems.
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Affiliation(s)
- Le Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Sheng Ju
- School of Physical Science and Technology, Soochow University, Suzhou 215006, China
| | - Lu You
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Yajun Qi
- School of Materials Science and Engineering, Hubei University, Wuhan 430062, China
| | - Yu-wei Guo
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Peng Ren
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Yang Zhou
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Junling Wang
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
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19
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Mikheev E, Hauser AJ, Himmetoglu B, Moreno NE, Janotti A, Van de Walle CG, Stemmer S. Tuning bad metal and non-Fermi liquid behavior in a Mott material: Rare-earth nickelate thin films. SCIENCE ADVANCES 2015; 1:e1500797. [PMID: 26601140 PMCID: PMC4640588 DOI: 10.1126/sciadv.1500797] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 08/28/2015] [Indexed: 05/05/2023]
Abstract
Resistances that exceed the Mott-Ioffe-Regel limit (known as bad metal behavior) and non-Fermi liquid behavior are ubiquitous features of the normal state of many strongly correlated materials. We establish the conditions that lead to bad metal and non-Fermi liquid phases in NdNiO3, which exhibits a prototype bandwidth-controlled metal-insulator transition. We show that resistance saturation is determined by the magnitude of Ni eg orbital splitting, which can be tuned by strain in epitaxial films, causing the appearance of bad metal behavior under certain conditions. The results shed light on the nature of a crossover to a non-Fermi liquid metal phase and provide a predictive criterion for Anderson localization. They elucidate a seemingly complex phase behavior as a function of film strain and confinement and provide guidelines for orbital engineering and novel devices.
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20
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Upton MH, Choi Y, Park H, Liu J, Meyers D, Chakhalian J, Middey S, Kim JW, Ryan PJ. Novel Electronic Behavior Driving NdNiO3 Metal-Insulator Transition. PHYSICAL REVIEW LETTERS 2015; 115:036401. [PMID: 26230808 DOI: 10.1103/physrevlett.115.036401] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Indexed: 05/27/2023]
Abstract
We present evidence that the metal-insulator transition (MIT) in a tensile-strained NdNiO3 (NNO) film is facilitated by a redistribution of electronic density and that it neither requires Ni charge disproportionation nor a symmetry change [U. Staub et al., Phys. Rev. Lett. 88, 126402 (2002); R. Jaramillo et al., Nat. Phys. 10, 304 (2014)]. Given that epitaxial tensile strain in thin NNO films induces preferential occupancy of the e(g) d(x(2)-y(2)) orbital we propose that the larger transfer integral of this orbital state with the O 2p orbital state mediates a redistribution of electronic density from the Ni atom. A decrease in the Ni d(x(2)-y(2)) orbital occupation is directly observed by resonant inelastic x-ray scattering below the MIT temperature. Furthermore, an increase in the Nd charge occupancy is measured by x-ray absorption at the Nd L(3) edge. Both spin-orbit coupling and crystal field effects combine to break the degeneracy of the Nd 5d states, shifting the energy of the Nd e(g) d(x(2)-y(2)) orbit towards the Fermi level, allowing the A site to become an active acceptor during the MIT. This work identifies the relocation of electrons from the Ni 3d to the Nd 5d orbitals across the MIT. We propose that the insulating gap opens between the Ni 3d and O 2p states, resulting from Ni 3d electron localization. The transition seems to be neither a purely Mott-Hubbard transition nor a simple charge transfer.
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Affiliation(s)
- M H Upton
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Yongseong Choi
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Hyowon Park
- Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA
- Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Jian Liu
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - D Meyers
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - J Chakhalian
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - S Middey
- Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Jong-Woo Kim
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
| | - Philip J Ryan
- Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA
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21
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Latent instabilities in metallic LaNiO3 films by strain control of Fermi-surface topology. Sci Rep 2015; 5:8746. [PMID: 25735658 PMCID: PMC4348653 DOI: 10.1038/srep08746] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/02/2015] [Indexed: 11/08/2022] Open
Abstract
Strain control is one of the most promising avenues to search for new emergent phenomena in transition-metal-oxide films. Here, we investigate the strain-induced changes of electronic structures in strongly correlated LaNiO3 (LNO) films, using angle-resolved photoemission spectroscopy and the dynamical mean-field theory. The strongly renormalized eg-orbital bands are systematically rearranged by misfit strain to change its fermiology. As tensile strain increases, the hole pocket centered at the A point elongates along the kz-axis and seems to become open, thus changing Fermi-surface (FS) topology from three- to quasi-two-dimensional. Concomitantly, the FS shape becomes flattened to enhance FS nesting. A FS superstructure with Q1 = (1/2,1/2,1/2) appears in all LNO films, while a tensile-strained LNO film has an additional Q2 = (1/4,1/4,1/4) modulation, indicating that some instabilities are present in metallic LNO films. Charge disproportionation and spin-density-wave fluctuations observed in other nickelates might be their most probable origins.
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22
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Hepting M, Minola M, Frano A, Cristiani G, Logvenov G, Schierle E, Wu M, Bluschke M, Weschke E, Habermeier HU, Benckiser E, Le Tacon M, Keimer B. Tunable Charge and Spin Order in PrNiO_{3} Thin Films and Superlattices. PHYSICAL REVIEW LETTERS 2014; 113:227206. [PMID: 25494088 DOI: 10.1103/physrevlett.113.227206] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Indexed: 06/04/2023]
Abstract
We use polarized Raman scattering to probe lattice vibrations and charge ordering in 12 nm thick, epitaxially strained PrNiO_{3} films, and in superlattices of PrNiO_{3} with the band insulator PrAlO_{3}. A carefully adjusted confocal geometry is used to eliminate the substrate contribution to the Raman spectra. In films and superlattices under tensile strain which undergo a metal-insulator transition upon cooling, the Raman spectra reveal phonon modes characteristic of charge ordering. These anomalous phonons do not appear in compressively strained films, which remain metallic at all temperatures. For superlattices under compressive strain, the Raman spectra show no evidence of anomalous phonons indicative of charge ordering, while complementary resonant x-ray scattering experiments reveal antiferromagnetic order associated with a modest increase in resistivity upon cooling. This confirms theoretical predictions of a spin density wave phase driven by spatial confinement of the conduction electrons.
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Affiliation(s)
- M Hepting
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - M Minola
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - A Frano
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany and Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - G Cristiani
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - G Logvenov
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - E Schierle
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - M Wu
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - M Bluschke
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany and Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - E Weschke
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - H-U Habermeier
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - E Benckiser
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - M Le Tacon
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, 70569 Stuttgart, Germany
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23
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King PDC, Wei HI, Nie YF, Uchida M, Adamo C, Zhu S, He X, Božović I, Schlom DG, Shen KM. Atomic-scale control of competing electronic phases in ultrathin LaNiO₃. NATURE NANOTECHNOLOGY 2014; 9:443-7. [PMID: 24705511 DOI: 10.1038/nnano.2014.59] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 02/21/2014] [Indexed: 05/27/2023]
Abstract
In an effort to scale down electronic devices to atomic dimensions, the use of transition-metal oxides may provide advantages over conventional semiconductors. Their high carrier densities and short electronic length scales are desirable for miniaturization, while strong interactions that mediate exotic phase diagrams open new avenues for engineering emergent properties. Nevertheless, understanding how their correlated electronic states can be manipulated at the nanoscale remains challenging. Here, we use angle-resolved photoemission spectroscopy to uncover an abrupt destruction of Fermi liquid-like quasiparticles in the correlated metal LaNiO₃ when confined to a critical film thickness of two unit cells. This is accompanied by the onset of an insulating phase as measured by electrical transport. We show how this is driven by an instability to an incipient order of the underlying quantum many-body system, demonstrating the power of artificial confinement to harness control over competing phases in complex oxides with atomic-scale precision.
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Affiliation(s)
- P D C King
- 1] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA [2] Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - H I Wei
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - Y F Nie
- 1] Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA [2] Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - M Uchida
- Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
| | - C Adamo
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - S Zhu
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - X He
- Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - I Božović
- Brookhaven National Laboratory, Upton, New York 11973-5000, USA
| | - D G Schlom
- 1] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA [2] Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
| | - K M Shen
- 1] Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, USA [2] Laboratory of Atomic and Solid State Physics, Department of Physics, Cornell University, Ithaca, New York 14853, USA
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24
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Johnston S, Mukherjee A, Elfimov I, Berciu M, Sawatzky GA. Charge disproportionation without charge transfer in the rare-earth-element nickelates as a possible mechanism for the metal-insulator transition. PHYSICAL REVIEW LETTERS 2014; 112:106404. [PMID: 24679313 DOI: 10.1103/physrevlett.112.106404] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Indexed: 05/27/2023]
Abstract
We study a model for the metal-insulator (M-I) transition in the rare-earth-element nickelates RNiO3, based upon a negative charge transfer energy and coupling to a rocksaltlike lattice distortion of the NiO6 octahedra. Using exact diagonalization and the Hartree-Fock approximation we demonstrate that electrons couple strongly to these distortions. For small distortions the system is metallic, with a ground state of predominantly d8L character, where L_ denotes a ligand hole. For sufficiently large distortions (δdNi-O∼0.05-0.10 Å), however, a gap opens at the Fermi energy as the system enters a periodically distorted state alternating along the three crystallographic axes, with (d8L_2)S=0(d8)S=1 character, where S is the total spin. Thus the M-I transition may be viewed as being driven by an internal volume "collapse" where the NiO6 octahedra with two ligand holes shrink around their central Ni, while the remaining octahedra expand accordingly, resulting in the (1/2, 1/2, 1/2) superstructure observed in x-ray diffraction in the insulating phase. This insulating state is an example of charge ordering achieved without any actual movement of the charge.
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Affiliation(s)
- Steve Johnston
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Anamitra Mukherjee
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Ilya Elfimov
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Mona Berciu
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - George A Sawatzky
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1 and Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4 and Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
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25
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Frano A, Schierle E, Haverkort MW, Lu Y, Wu M, Blanco-Canosa S, Nwankwo U, Boris AV, Wochner P, Cristiani G, Habermeier HU, Logvenov G, Hinkov V, Benckiser E, Weschke E, Keimer B. Orbital control of noncollinear magnetic order in nickel oxide heterostructures. PHYSICAL REVIEW LETTERS 2013; 111:106804. [PMID: 25166693 DOI: 10.1103/physrevlett.111.106804] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 07/10/2013] [Indexed: 06/03/2023]
Abstract
We have used resonant x-ray diffraction to develop a detailed description of antiferromagnetic ordering in epitaxial superlattices based on two-unit-cell thick layers of the strongly correlated metal LaNiO3. We also report reference experiments on thin films of PrNiO3 and NdNiO3. The resulting data indicate a spiral state whose polarization plane can be controlled by adjusting the Ni d-orbital occupation via two independent mechanisms: epitaxial strain and spatial confinement of the valence electrons. The data are discussed in light of recent theoretical predictions.
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Affiliation(s)
- A Frano
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany and Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - E Schierle
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - M W Haverkort
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - Y Lu
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - M Wu
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - S Blanco-Canosa
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - U Nwankwo
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - A V Boris
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - P Wochner
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - G Cristiani
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - H U Habermeier
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - G Logvenov
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - V Hinkov
- Quantum Matter Institute, University of British Columbia, Vancouver, British Colombia V6T 1Z1, Canada
| | - E Benckiser
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
| | - E Weschke
- Helmholtz-Zentrum Berlin für Materialien und Energie, Wilhelm-Conrad-Röntgen-Campus BESSY II, Albert-Einstein-Strasse 15, D-12489 Berlin, Germany
| | - B Keimer
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany
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