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Vallejo KD, Kabir F, Poudel N, Marianetti CA, Hurley DH, Simmonds PJ, Dennett CA, Gofryk K. Advances in actinide thin films: synthesis, properties, and future directions. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:123101. [PMID: 36179676 DOI: 10.1088/1361-6633/ac968e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Actinide-based compounds exhibit unique physics due to the presence of 5f electrons, and serve in many cases as important technological materials. Targeted thin film synthesis of actinide materials has been successful in generating high-purity specimens in which to study individual physical phenomena. These films have enabled the study of the unique electron configuration, strong mass renormalization, and nuclear decay in actinide metals and compounds. The growth of these films, as well as their thermophysical, magnetic, and topological properties, have been studied in a range of chemistries, albeit far fewer than most classes of thin film systems. This relative scarcity is the result of limited source material availability and safety constraints associated with the handling of radioactive materials. Here, we review recent work on the synthesis and characterization of actinide-based thin films in detail, describing both synthesis methods and modeling techniques for these materials. We review reports on pyrometallurgical, solution-based, and vapor deposition methods. We highlight the current state-of-the-art in order to construct a path forward to higher quality actinide thin films and heterostructure devices.
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Affiliation(s)
- Kevin D Vallejo
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
| | - Firoza Kabir
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
- Glenn T Seaborg Institute, Idaho National Laboratory, Idaho Falls, ID 83415, United States of America
| | - Narayan Poudel
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
| | - Chris A Marianetti
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, United States of America
| | - David H Hurley
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
| | - Paul J Simmonds
- Department of Physics, Boise State University, Boise, ID 83725, United States of America
- Micron School of Materials Science and Engineering, Boise State University, Boise, ID 83725,United States of America
| | - Cody A Dennett
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
| | - Krzysztof Gofryk
- Condensed Matter and Materials Physics, Idaho National Laboratory, Idaho Falls, ID 83415,United States of America
- Glenn T Seaborg Institute, Idaho National Laboratory, Idaho Falls, ID 83415, United States of America
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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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Meng M, Sun Y, Li Y, An Q, Wang Z, Lin Z, Yang F, Zhu X, Gao P, Guo J. Three dimensional band-filling control of complex oxides triggered by interfacial electron transfer. Nat Commun 2021; 12:2447. [PMID: 33907193 PMCID: PMC8079372 DOI: 10.1038/s41467-021-22790-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 03/29/2021] [Indexed: 11/09/2022] Open
Abstract
The d-band-filling of transition metals in complex oxides plays an essential role in determining their structural, electronic and magnetic properties. Traditionally, at the oxide heterointerface, band-filling control has been achieved via electrostatic modification in the structure of field-effect transistors or electron transfer, which is limited to the quasi-two-dimension at the interface. Here we report a three-dimensional (3D) band-filling control by changing the local lattice coordination in a designed oxide heterostructure. At the LaCoO3/LaTiO3 heterointerface, due to the Fermi level mismatch, electrons transfer from LaTiO3 to LaCoO3. This triggers destabilisation of the CoO6 octahedrons, i.e. the formation of lattice configurations with a reduced Co valence. The associated oxygen migration results in the 3D topotactic phase transition of LaCoO3. Tuned by the thickness of LaTiO3, different crystalline phases and band-fillings of Co occur, leading to the emergence of different magnetic ground states.
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Affiliation(s)
- Meng Meng
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Yuanwei Sun
- International Center for Quantum Materials, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Yuehui Li
- International Center for Quantum Materials, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China
| | - Qichang An
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhenzhen Wang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zijian Lin
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Fang Yang
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China
| | - Xuetao Zhu
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China.,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China.,Songshan Lake Materials Laboratory, Dongguan, Guangdong, China
| | - Peng Gao
- International Center for Quantum Materials, and Electron Microscopy Laboratory, School of Physics, Peking University, Beijing, China. .,Collaborative Innovation Center of Quantum Matter, Beijing, China.
| | - Jiandong Guo
- Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing, China. .,School of Physical Sciences, University of Chinese Academy of Sciences, Beijing, China. .,Songshan Lake Materials Laboratory, Dongguan, Guangdong, China. .,Beijing Academy of Quantum Information Sciences, Beijing, China.
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Abstract
Point defects, such as oxygen vacancies, control the physical properties of complex oxides, relevant in active areas of research from superconductivity to resistive memory to catalysis. In most oxide semiconductors, electrons that are associated with oxygen vacancies occupy the conduction band, leading to an increase in the electrical conductivity. Here we demonstrate, in contrast, that in the correlated-electron perovskite rare-earth nickelates, RNiO3 (R is a rare-earth element such as Sm or Nd), electrons associated with oxygen vacancies strongly localize, leading to a dramatic decrease in the electrical conductivity by several orders of magnitude. This unusual behavior is found to stem from the combination of crystal field splitting and filling-controlled Mott-Hubbard electron-electron correlations in the Ni 3d orbitals. Furthermore, we show the distribution of oxygen vacancies in NdNiO3 can be controlled via an electric field, leading to analog resistance switching behavior. This study demonstrates the potential of nickelates as testbeds to better understand emergent physics in oxide heterostructures as well as candidate systems in the emerging fields of artificial intelligence.
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Interfacial charge-transfer Mott state in iridate-nickelate superlattices. Proc Natl Acad Sci U S A 2019; 116:19863-19868. [PMID: 31527227 DOI: 10.1073/pnas.1907043116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We investigate [Formula: see text]/[Formula: see text] superlattices in which we observe a full electron transfer at the interface from Ir to Ni, triggering a massive structural and electronic reconstruction. Through experimental characterization and first-principles calculations, we determine that a large crystal field splitting from the distorted interfacial [Formula: see text] octahedra surprisingly dominates over the spin-orbit coupling and together with the Hund's coupling results in the high-spin (S = 1) configurations on both the Ir and Ni sites. This demonstrates the power of interfacial charge transfer in coupling lattice, charge, orbital, and spin degrees of freedom, opening fresh avenues of investigation of quantum states in oxide superlattices.
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Miháliková I, Friák M, Jirásková Y, Holec D, Koutná N, Šob M. Impact of Nano-Scale Distribution of Atoms on Electronic and Magnetic Properties of Phases in Fe-Al Nanocomposites: An Ab Initio Study. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E1059. [PMID: 30558362 PMCID: PMC6316398 DOI: 10.3390/nano8121059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 11/17/2022]
Abstract
Quantum-mechanical calculations are applied to examine magnetic and electronic properties of phases appearing in binary Fe-Al-based nanocomposites. The calculations are carried out using the Vienna Ab-initio Simulation Package which implements density functional theory and generalized gradient approximation. The focus is on a disordered solid solution with 18.75 at. % Al in body-centered-cubic ferromagnetic iron, so-called α -phase, and an ordered intermetallic compound Fe 3 Al with the D0 3 structure. In order to reveal the impact of the actual atomic distribution in the disordered Fe-Al α -phase three different special quasi-random structures with or without the 1st and/or 2nd nearest-neighbor Al-Al pairs are used. According to our calculations, energy decreases when eliminating the 1st and 2nd nearest neighbor Al-Al pairs. On the other hand, the local magnetic moments of the Fe atoms decrease with Al concentration in the 1st coordination sphere and increase if the concentration of Al atoms increases in the 2nd one. Furthermore, when simulating Fe-Al/Fe 3 Al nanocomposites (superlattices), changes of local magnetic moments of the Fe atoms up to 0.5 μ B are predicted. These changes very sensitively depend on both the distribution of atoms and the crystallographic orientation of the interfaces.
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Affiliation(s)
- Ivana Miháliková
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
| | - Martin Friák
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - Yvonna Jirásková
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Nikola Koutná
- Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Institute of Materials Science and Technology, TU Wien, Getreidemarkt 9, A-1060 Vienna, Austria.
| | - Mojmír Šob
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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Friák M, Holec D, Šob M. Quantum-Mechanical Study of Nanocomposites with Low and Ultra-Low Interface Energies. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E1057. [PMID: 30558300 PMCID: PMC6316202 DOI: 10.3390/nano8121057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 12/08/2018] [Accepted: 12/12/2018] [Indexed: 11/17/2022]
Abstract
We applied first-principles electronic structure calculations to study structural, thermodynamic and elastic properties of nanocomposites exhibiting nearly perfect match of constituting phases. In particular, two combinations of transition-metal disilicides and one pair of magnetic phases containing the Fe and Al atoms with different atomic ordering were considered. Regarding the disilicides, nanocomposites MoSi 2 /WSi 2 with constituents crystallizing in the tetragonal C11 b structure and TaSi 2 /NbSi 2 with individual phases crystallizing in the hexagonal C40 structure were simulated. Constituents within each pair of materials exhibit very similar structural and elastic properties and for their nanocomposites we obtained ultra-low (nearly zero) interface energy (within the error bar of our calculations, i.e., about 0.005 J/m 2 ). The interface energy was found to be nearly independent on the width of individual constituents within the nanocomposites and/or crystallographic orientation of the interfaces. As far as the nanocomposites containing Fe and Al were concerned, we simulated coherent superlattices formed by an ordered Fe 3 Al intermetallic compound and a disordered Fe-Al phase with 18.75 at.% Al, the α -phase. Both phases were structurally and elastically quite similar but the disordered α -phase lacked a long-range periodicity. To determine the interface energy in these nanocomposites, we simulated seven different distributions of atoms in the α -phase interfacing the Fe 3 Al intermetallic compound. The resulting interface energies ranged from ultra low to low values, i.e., from 0.005 to 0.139 J/m 2 . The impact of atomic distribution on the elastic properties was found insignificant but local magnetic moments of the iron atoms depend sensitively on the type and distribution of surrounding atoms.
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Affiliation(s)
- Martin Friák
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Mojmír Šob
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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Friák M, Kroupa P, Holec D, Šob M. An Ab Initio Study of Pressure-Induced Reversal of Elastically Stiff and Soft Directions in YN and ScN and Its Effect in Nanocomposites Containing These Nitrides. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E1049. [PMID: 30558137 PMCID: PMC6316261 DOI: 10.3390/nano8121049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/10/2018] [Accepted: 12/11/2018] [Indexed: 11/16/2022]
Abstract
Using quantum-mechanical calculations of second- and third-order elastic constants for YN and ScN with the rock-salt (B1) structure, we predict that these materials change the fundamental type of their elastic anisotropy by rather moderate hydrostatic pressures of a few GPa. In particular, YN with its zero-pressure elastic anisotropy characterized by the Zener anisotropy ratio A Z = 2 C 44 / ( C 11 - C 12 ) = 1.046 becomes elastically isotropic at the hydrostatic pressure of 1.2 GPa. The lowest values of the Young's modulus (so-called soft directions) change from 〈100〉 (in the zero-pressure state) to the 〈111〉 directions (for pressures above 1.2 GPa). It means that the crystallographic orientations of stiffest (also called hard) elastic response and those of the softest one are reversed when comparing the zero-pressure state with that for pressures above the critical level. Qualitatively, the same type of reversal is predicted for ScN with the zero-pressure value of the Zener anisotropy factor A Z = 1.117 and the critical pressure of about 6.5 GPa. Our predictions are based on both second-order and third-order elastic constants determined for the zero-pressure state but the anisotropy change is then verified by explicit calculations of the second-order elastic constants for compressed states. Both materials are semiconductors in the whole range of studied pressures. Our phonon calculations further reveal that the change in the type of the elastic anisotropy has only a minor impact on the vibrational properties. Our simulations of biaxially strained states of YN demonstrate that a similar change in the elastic anisotropy can be achieved also under stress conditions appearing, for example, in coherently co-existing nanocomposites such as superlattices. Finally, after selecting ScN and PdN (both in B1 rock-salt structure) as a pair of suitable candidate materials for such a superlattice (due to the similarity of their lattice parameters), our calculations of such a coherent nanocomposite results again in a reversed elastic anisotropy (compared with the zero-pressure state of ScN).
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Affiliation(s)
- Martin Friák
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
| | - Pavel Kroupa
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Physics, Imperial College London, Prince Consort Road, London SW7 2BP, UK.
| | - David Holec
- Department of Materials Science, Montanuniversität Leoben, Franz-Josef-Strasse 18, A-8700 Leoben, Austria.
| | - Mojmír Šob
- Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-616 62 Brno, Czech Republic.
- Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, CZ-611 37 Brno, Czech Republic.
- Central European Institute of Technology, CEITEC MU, Masaryk University, Kamenice 5, CZ-625 00 Brno, Czech Republic.
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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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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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12
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Chen H, Millis A. Design of new Mott multiferroics via complete charge transfer: promising candidates for bulk photovoltaics. Sci Rep 2017; 7:6142. [PMID: 28733597 PMCID: PMC5522466 DOI: 10.1038/s41598-017-06396-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/09/2017] [Indexed: 11/10/2022] Open
Abstract
Optimal materials to induce bulk photovoltaic effects should lack inversion symmetry and have an optical gap matching the energies of visible radiation. Ferroelectric perovskite oxides such as BaTiO3 and PbTiO3 exhibit substantial polarization and stability, but have the disadvantage of excessively large band gaps. We use both density functional theory and dynamical mean field theory calculations to design a new class of Mott multiferroics–double perovskite oxides A2VFeO6 (A = Ba, Pb, etc). While neither perovskite AVO3 nor AFeO3 is ferroelectric, in the double perovskite A2VFeO6 a ‘complete’ charge transfer from V to Fe leads to a non-bulk-like charge configuration–an empty V-d shell and a half-filled Fe-d shell, giving rise to a polarization comparable to that of ferroelectric ATiO3. Different from nonmagnetic ATiO3, the new double perovskite oxides have an antiferromagnetic ground state and around room temperatures, are paramagnetic Mott insulators. Most importantly, the V d0 state significantly reduces the band gap of A2VFeO6, making it smaller than that of ATiO3 and BiFeO3 and rendering the new multiferroics a promising candidate to induce bulk photovoltaic effects.
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Affiliation(s)
- Hanghui Chen
- NYU-ECNU Institute of Physics, NYU Shanghai, Shanghai, 200062, China. .,Department of Physics, New York University, New York, NY, 10002, USA.
| | - Andrew Millis
- Department of Physics, Columbia University, New York, NY, 10027, USA
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Chen H, Millis A. Charge transfer driven emergent phenomena in oxide heterostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:243001. [PMID: 28437253 DOI: 10.1088/1361-648x/aa6efe] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Complex oxides exhibit many intriguing phenomena, including metal-insulator transition, ferroelectricity/multiferroicity, colossal magnetoresistance and high transition temperature superconductivity. Advances in epitaxial thin film growth techniques enable us to combine different complex oxides with atomic precision and form an oxide heterostructure. Recent theoretical and experimental work has shown that charge transfer across oxide interfaces generally occurs and leads to a great diversity of emergent interfacial properties which are not exhibited by bulk constituents. In this report, we review mechanisms and physical consequence of charge transfer across interfaces in oxide heterostructures. Both theoretical proposals and experimental measurements of various oxide heterostructures are discussed and compared. We also review the theoretical methods that are used to calculate charge transfer across oxide interfaces and discuss the success and challenges in theory. Finally, we present a summary and perspectives for future research.
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Affiliation(s)
- Hanghui Chen
- NYU-ECNU Institute of Physics, New York University Shanghai, 200062, People's Republic of China. Department of Physics, New York University, New York, NY 10002, United States of America
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Park SY, Kumar A, Rabe KM. Charge-Order-Induced Ferroelectricity in LaVO_{3}/SrVO_{3} Superlattices. PHYSICAL REVIEW LETTERS 2017; 118:087602. [PMID: 28282196 DOI: 10.1103/physrevlett.118.087602] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Indexed: 06/06/2023]
Abstract
The structure and properties of the 1∶1 superlattice of LaVO_{3} and SrVO_{3} are investigated with a first-principles density-functional-theory-plus-U (DFT+U) method. The lowest energy states are antiferromagnetic charge-ordered Mott-insulating phases. In one of these insulating phases, layered charge ordering combines with the layered La/Sr cation ordering to produce a polar structure with a large nonzero spontaneous polarization normal to the interfaces. This polarization, comparable to that of conventional ferroelectrics, is produced by electron transfer between the V^{3+} and V^{4+} layers. The energy of this normal-polarization state relative to the ground state is only 3 meV per vanadium. Under tensile strain, this energy difference can be further reduced, suggesting that the normal-polarization state can be induced by an electric field applied normal to the superlattice layers, yielding an antiferroelectric double-hysteresis loop. If the system does not switch back to the ground state on removal of the field, a ferroelectric-type hysteresis loop could be observed.
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Affiliation(s)
- Se Young Park
- Department of Physics & Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
| | - Anil Kumar
- Department of Physics & Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Karin M Rabe
- Department of Physics & Astronomy, Rutgers University, Piscataway, New Jersey 08854, USA
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15
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Lin CK, Chuang CC, Raghunath P, Srinivasadesikan V, Wang T, Lin M. Quantum-chemical prediction of the effects of Ni-loading on the hydrogenation and water-splitting efficiency of TiO2 nanoparticles with an experimental test. Chem Phys Lett 2017. [DOI: 10.1016/j.cplett.2016.10.082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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16
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Fabbris G, Meyers D, Okamoto J, Pelliciari J, Disa AS, Huang Y, Chen ZY, Wu WB, Chen CT, Ismail-Beigi S, Ahn CH, Walker FJ, Huang DJ, Schmitt T, Dean MPM. Orbital Engineering in Nickelate Heterostructures Driven by Anisotropic Oxygen Hybridization rather than Orbital Energy Levels. PHYSICAL REVIEW LETTERS 2016; 117:147401. [PMID: 27740843 DOI: 10.1103/physrevlett.117.147401] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Indexed: 06/06/2023]
Abstract
Resonant inelastic x-ray scattering is used to investigate the electronic origin of orbital polarization in nickelate heterostructures taking LaTiO_{3}-LaNiO_{3}-3×(LaAlO_{3}), a system with exceptionally large polarization, as a model system. We find that heterostructuring generates only minor changes in the Ni 3d orbital energy levels, contradicting the often-invoked picture in which changes in orbital energy levels generate orbital polarization. Instead, O K-edge x-ray absorption spectroscopy demonstrates that orbital polarization is caused by an anisotropic reconstruction of the oxygen ligand hole states. This provides an explanation for the limited success of theoretical predictions based on tuning orbital energy levels and implies that future theories should focus on anisotropic hybridization as the most effective means to drive large changes in electronic structure and realize novel emergent phenomena.
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Affiliation(s)
- G Fabbris
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - D Meyers
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - J Okamoto
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - J Pelliciari
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - A S Disa
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Y Huang
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - Z-Y Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - W B Wu
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - C T Chen
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
| | - S Ismail-Beigi
- 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
| | - C H Ahn
- 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
| | - F J Walker
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - D J Huang
- National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
- Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - T Schmitt
- Research Department "Synchrotron Radiation and Nanotechnology", Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
| | - M P M Dean
- Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, New York 11973, USA
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17
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Grisolia M, Varignon J, Sanchez-Santolino G, Arora A, Valencia S, Varela M, Abrudan R, Weschke E, Schierle E, Rault J, Rueff JP, Barthélémy A, Santamaria J, Bibes M. Hybridization-controlled charge transfer and induced magnetism at correlated oxide interfaces. NATURE PHYSICS 2016; 12:484-492. [PMID: 27158255 PMCID: PMC4856211 DOI: 10.1038/nphys3627] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 12/04/2015] [Indexed: 05/22/2023]
Abstract
At interfaces between conventional materials, band bending and alignment are classically controlled by differences in electrochemical potential. Applying this concept to oxides in which interfaces can be polar and cations may adopt a mixed valence has led to the discovery of novel two-dimensional states between simple band insulators such as LaAlO3 and SrTiO3. However, many oxides have a more complex electronic structure, with charge, orbital and/or spin orders arising from strong Coulomb interactions between transition metal and oxygen ions. Such electronic correlations offer a rich playground to engineer functional interfaces but their compatibility with the classical band alignment picture remains an open question. Here we show that beyond differences in electron affinities and polar effects, a key parameter determining charge transfer at correlated oxide interfaces is the energy required to alter the covalence of the metal-oxygen bond. Using the perovskite nickelate (RNiO3) family as a template, we probe charge reconstruction at interfaces with gadolinium titanate GdTiO3. X-ray absorption spectroscopy shows that the charge transfer is thwarted by hybridization effects tuned by the rare-earth (R) size. Charge transfer results in an induced ferromagnetic-like state in the nickelate, exemplifying the potential of correlated interfaces to design novel phases. Further, our work clarifies strategies to engineer two-dimensional systems through the control of both doping and covalence.
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Affiliation(s)
- M.N. Grisolia
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - J. Varignon
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - G. Sanchez-Santolino
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - A. Arora
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - S. Valencia
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - M. Varela
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
- Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - R. Abrudan
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
- Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - E. Weschke
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - E. Schierle
- Helmholtz-Zentrum Berlin für Materialen & Energie, Albert-Einstein-Strasse 15, 12489 Berlin, Germany
| | - J.E. Rault
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - J.-P. Rueff
- Synchrotron SOLEIL, L'Orme des Merisiers Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - A. Barthélémy
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
| | - J. Santamaria
- GFMC, Departamento Física Aplicada III, Universidad Complutense Madrid, 28040 Madrid, Spain, and Laboratorio de Heteroestructuras con aplicación en Spintronica, Unidad Asociada CSIC/Universidad Complutense de Madrid, Sor Juana Inés de la Cruz, 3, 28049 Madrid, Spain
| | - M. Bibes
- Unité Mixte de Physique CNRS/Thales, 1 avenue A. Fresnel, 91767 Palaiseau, France, and Université Paris-Sud, 91405 Orsay, France
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18
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Engineered Mott ground state in a LaTiO(3+δ)/LaNiO3 heterostructure. Nat Commun 2016; 7:10418. [PMID: 26791402 PMCID: PMC4735946 DOI: 10.1038/ncomms10418] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 12/09/2015] [Indexed: 11/08/2022] Open
Abstract
In pursuit of creating cuprate-like electronic and orbital structures, artificial heterostructures based on LaNiO3 have inspired a wealth of exciting experimental and theoretical results. However, to date there is a very limited experimental understanding of the electronic and orbital states emerging from interfacial charge transfer and their connections to the modified band structure at the interface. Towards this goal, we have synthesized a prototypical superlattice composed of a correlated metal LaNiO3 and a doped Mott insulator LaTiO3+δ, and investigated its electronic structure by resonant X-ray absorption spectroscopy combined with X-ray photoemission spectroscopy, electrical transport and theory calculations. The heterostructure exhibits interfacial charge transfer from Ti to Ni sites, giving rise to an insulating ground state with orbital polarization and eg orbital band splitting. Our findings demonstrate how the control over charge at the interface can be effectively used to create exotic electronic, orbital and spin states. Interfaces between two dissimilar transition metal oxides can exhibit emergent strongly correlated electronic and magnetic states due to charge transfer and electronic reconfiguration. Here, the authors synthesize and investigate an exotic Mott ground state in LaTiO3+δ/LaNiO3 heterostructures.
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19
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Disa AS, Kumah DP, Malashevich A, Chen H, Arena DA, Specht ED, Ismail-Beigi S, Walker FJ, Ahn CH. Orbital engineering in symmetry-breaking polar heterostructures. PHYSICAL REVIEW LETTERS 2015; 114:026801. [PMID: 25635555 DOI: 10.1103/physrevlett.114.026801] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Indexed: 05/21/2023]
Abstract
We experimentally demonstrate a novel approach to substantially modify orbital occupations and symmetries in electronically correlated oxides. In contrast to methods using strain or confinement, this orbital tuning is achieved by exploiting charge transfer and inversion symmetry breaking using atomically layered heterostructures. We illustrate the technique in the LaTiO_{3}-LaNiO_{3}-LaAlO_{3} system; a combination of x-ray absorption spectroscopy and ab initio theory reveals electron transfer and concomitant polar fields, resulting in a ∼50% change in the occupation of Ni d orbitals. This change is sufficiently large to remove the orbital degeneracy of bulk LaNiO_{3} and creates an electronic configuration approaching a single-band Fermi surface. Furthermore, we theoretically show that such three-component heterostructuring is robust and tunable by choice of insulator in the heterostructure, providing a general method for engineering orbital configurations and designing novel electronic systems.
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Affiliation(s)
- Ankit S Disa
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Divine P Kumah
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Andrei Malashevich
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Hanghui Chen
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA and Department of Physics, Columbia University, New York, New York 10027, USA and Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
| | - Dario A Arena
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Eliot D Specht
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Sohrab Ismail-Beigi
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA and Departments of Physics and Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, USA
| | - F J Walker
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA
| | - Charles H Ahn
- Center for Research on Interface Structures and Phenomena, Yale University, New Haven, Connecticut 06511, USA and Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA and Departments of Physics and Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06511, USA
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20
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McLeod JA, Kurmaev EZ, Perez I, Green RJ, Xing LY, Wang XC, Jin CQ, Moewes A. Electronic structure and spin trapping in LiMnAs and LiFeAs:Mn. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:015504. [PMID: 25478917 DOI: 10.1088/0953-8984/27/1/015504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The electronic structure of insulating antiferromagnetic LiMnAs is investigated using soft x-ray spectroscopy and compared to the electronic structure of metallic LiFeAs. Our calculations support the experimentally observed insulating antiferromagnetic order in LiMnAs. The x-ray absorption and resonant inelastic x-ray scattering spectra in LiFeAs and LiMnAs are adequately explained by the electronic structure alone, although it is possible that LiMnAs has significant electronic correlations driven by Hund's J coupling. Finally, we show evidence of a possible spin trap in Li(Fe0.95Mn0.05)As.
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Affiliation(s)
- J A McLeod
- Department of Physics and Engineering Physics, University of Saskatchewan, 116 Science Place, Saskatoon, Saskatchewan S7N 5E2, Canada
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21
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Kleibeuker JE, Zhong Z, Nishikawa H, Gabel J, Müller A, Pfaff F, Sing M, Held K, Claessen R, Koster G, Rijnders G. Electronic reconstruction at the isopolar LaTiO(3)/LaFeO(3) interface: an X-ray photoemission and density-functional theory study. PHYSICAL REVIEW LETTERS 2014; 113:237402. [PMID: 25526156 DOI: 10.1103/physrevlett.113.237402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Indexed: 06/04/2023]
Abstract
We report the formation of a nonmagnetic band insulator at the isopolar interface between the antiferromagnetic Mott-Hubbard insulator LaTiO_{3} and the antiferromagnetic charge transfer insulator LaFeO_{3}. By density-functional theory calculations, we find that the formation of this interface state is driven by the combination of O band alignment and crystal field splitting energy of the t_{2g} and e_{g} bands. As a result of these two driving forces, the Fe 3d bands rearrange and electrons are transferred from Ti to Fe. This picture is supported by x-ray photoelectron spectroscopy, which confirms the rearrangement of the Fe 3d bands and reveals an unprecedented charge transfer up to 1.2±0.2 e^{-}/interface unit cell in our LaTiO_{3}/LaFeO_{3} heterostructures.
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Affiliation(s)
- J E Kleibeuker
- Faculty of Science and Technology and MESA+Institute for Nanotechnology, University of Twente, 7500 AE Enschede, Netherlands and Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - Z Zhong
- Institute of Solid State Physics, Vienna University of Technology, A-1040 Vienna, Austria
| | - H Nishikawa
- Faculty of Biology-Oriented Science and Technology, Kinki University, Kinokawa 649-6493, Japan
| | - J Gabel
- Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - A Müller
- Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - F Pfaff
- Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - M Sing
- Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - K Held
- Institute of Solid State Physics, Vienna University of Technology, A-1040 Vienna, Austria
| | - R Claessen
- Physikalisches Institut, University of Würzburg, 97074 Würzburg, Germany
| | - G Koster
- Faculty of Science and Technology and MESA+Institute for Nanotechnology, University of Twente, 7500 AE Enschede, Netherlands
| | - G Rijnders
- Faculty of Science and Technology and MESA+Institute for Nanotechnology, University of Twente, 7500 AE Enschede, Netherlands
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22
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Han MJ, van Veenendaal M. Fermi level density of states modulation without charge transfer in nickelate superlattices. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:145501. [PMID: 24637347 DOI: 10.1088/0953-8984/26/14/145501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
By using first-principles density functional theory calculations for (LaNiO3)m/(SrTiO3)n superlattices, we report a systematic electronic response to the interface geometry. It is found that the density of states at the Fermi level of metallic nickelate layers is significantly reduced without charge transfer in the vicinity of the interface to the insulating SrTiO3. This type of electronic state redistribution is clearly distinctive from other interface phenomena such as charge and orbital reconstruction. Our result sheds new light on the understanding of the nickelates and other transition-metal oxide heterostructures.
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Affiliation(s)
- Myung Joon Han
- Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea. Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA. Department of Physics, Northern Illinois University, De Kalb, IL 60115, USA
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