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Chen S, Xu Y, Chang X, Pan Y, Sun G, Wang X, Fu D, Pei C, Zhao ZJ, Su D, Gong J. Defective TiO x overlayers catalyze propane dehydrogenation promoted by base metals. Science 2024; 385:295-300. [PMID: 39024431 DOI: 10.1126/science.adp7379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 05/29/2024] [Indexed: 07/20/2024]
Abstract
The industrial catalysts utilized for propane dehydrogenation (PDH) to propylene, an important alternative to petroleum-based cracking processes, either use expensive metals or metal oxides that are environmentally unbenign. We report that a typically less-active oxide, titanium oxide (TiO2), can be combined with earth-abundant metallic nickel (Ni) to form an unconventional Ni@TiOx catalyst for efficient PDH. The catalyst demonstrates a 94% propylene selectivity at 40% propane conversion and superior stability under industrially relevant conditions. Complete encapsulation of Ni nanoparticles was allowed at elevated temperatures (>550°C). A mechanistic study suggested that the defective TiOx overlayer consisting of tetracoordinated Ti sites with oxygen vacancies is catalytically active. Subsurface metallic Ni acts as an electronic promoter to accelerate carbon-hydrogen bond activation and hydrogen (H2) desorption on the TiOx overlayer.
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Affiliation(s)
- Sai Chen
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Yiyi Xu
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Xin Chang
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
| | - Yue Pan
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Guodong Sun
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
| | - Xianhui Wang
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Donglong Fu
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Chunlei Pei
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Zhi-Jian Zhao
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
| | - Dong Su
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jinlong Gong
- School of Chemical Engineering and Technology, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center for Chemical Science and Engineering (Tianjin), Tianjin 300072, China
- International Joint Laboratory of Low-carbon Chemical Engineering of Ministry of Education, Tianjin 300350, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou 350207, China
- Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, China
- National Industry-Education Platform of Energy Storage, Tianjin University, Tianjin 300350, China
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Lu Q. How to Correctly Analyze 2p X-ray Photoelectron Spectra of 3d Transition-Metal Oxides: Pitfalls and Principles. ACS NANO 2024; 18:13973-13982. [PMID: 38776459 DOI: 10.1021/acsnano.4c03964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
Nanomaterials based on transition-metal oxides (TMOs) that contain late 3d transition metals (e.g., Mn, Fe, Co, Ni) have diverse properties and functionality that are related to the oxidation state of constituent transition-metal (TM) cations. X-ray photoelectron spectroscopy (XPS) of TM 2p orbitals has been widely used to quantify the TM oxidation state of TMOs. However, 2p XPS spectra of late 3d TM cations usually have complicated shapes due to the charge transfer between the TM cation and oxygen ligands (anions), which makes the analysis highly nontrivial. In this article, we will examine the validity of commonly used analysis methods based on either peak fitting or the shift of binding energy (BE). The different origins of the BE shift in XPS spectra will be discussed. We will then introduce a model to reproduce the complex shapes of TM 2p spectra, based on fundamental parameters that describe the TMO electronic structure.
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Affiliation(s)
- Qiyang Lu
- School of Engineering and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, P. R. China
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3
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Dhawan R, Balasubramanian P, Nautiyal T. Origins of multi-sublattice magnetism and superexchange interactions in double-double perovskite CaMnCrSbO 6. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2024; 36:305801. [PMID: 38157560 DOI: 10.1088/1361-648x/ad19a1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
The multi-sublattice magnetism and electronic structure in double-double perovskite compound CaMnCrSbO6is explored using density functional theory. The bulk magnetization and neutron diffraction suggest a ferrimagnetic order (TC∼49 K) between between Mn2+and Cr3+spins. Due to the non-equivalent Mn atoms (labelled as Mn(1) and Mn(2) which have tetrahedral and planar oxygen coordinations, respectively) and the Cr atom in the centre of distorted oxygen octahedron in the unit cell, the exchange interactions are more complex than that expected from a two sublattice magnetic system. The separations between the on-site energies of thed-orbitals of Mn(1), Mn(2) and Cr obtained from Wannier function analysis are in agreement with their expected crystal field splitting. While the DOS obtained from non spin-polarized calculations show a metallic character, starting from HubbardU = 0 eV the spin-polarized electronic structure calculations yield a ferrimagnetic insulating ground state. The band gap increases withUeff(U - J), thereby showing a Mott-Hubbard nature of the system. The inclusion of anti-site disorder in the calculations show decrease in band-gap and also reduction in the total magnetic moment. Due to the ∼90∘superexchange, nearest neighbour exchange constants obtained from DFT are an order of magnitude smaller than those reported for various magnetic perovskite and double-perovskite compounds. The Mn(1)-O-Mn(2) (out of plane and in-plane), Mn(1)-O-Cr and Mn(2)-O-Cr superexchange interactions are found to be anti-ferromagnetic, while the Cr-O-O-Cr super-superexchange is found to be ferromagnetic. The Mn(2)-O-Cr superexchange is weaker than the Mn(1)-O-Cr super-exchange, thus effectively resulting in ferrimagnetism. From a simple 3-site Hubbard model, we derived expressions for the antiferromagnetic superexchange strengthJAFMand also for the weaker ferromagneticJFM. The relative strengths ofJAFMfor the various superexchange interactions are in agreement with those obtained from DFT. The expression for Cr-O-O-Cr super-superexchange strength (J~SS), which has been derived considering a 4-site Hubbard model, predicts a ferromagnetic exchange in agreement with DFT. Finally, our mean field calculations reveal that assuming a set of four magnetic sub-lattices for Mn2+spins and a single magnetic sublattice for Cr3+spins yields a much improvedTC, while a simple two magnetic sublattice model yields a much higherTC.
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Affiliation(s)
- Rakshanda Dhawan
- Department of Physics, Indian Institute of Technology, Roorkee 247667, Uttarakhand, India
| | | | - Tashi Nautiyal
- Department of Physics, Indian Institute of Technology, Roorkee 247667, Uttarakhand, India
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Lombardi J, Yang L, Farahmand N, Ruffino A, Younes A, Spanier JE, Billinge SJL, O'Brien S. Structure and phase transitions in niobium and tantalum derived nanoscale transition metal perovskites, Ba(Ti,MV)O3, M=Nb,Ta. J Chem Phys 2024; 160:134702. [PMID: 38573849 DOI: 10.1063/5.0192488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/19/2024] [Indexed: 04/06/2024] Open
Abstract
The prospect of creating ferroelectric or high permittivity nanomaterials provides motivation for investigating complex transition metal oxides of the form Ba(Ti, MV)O3, where M = Nb or Ta. Solid state processing typically produces mixtures of crystalline phases, rarely beyond minimally doped Nb/Ta. Using a modified sol-gel method, we prepared single phase nanocrystals of Ba(Ti, M)O3. Compositional and elemental analysis puts the empirical formulas close to BaTi0.5Nb0.5O3-δ and BaTi0.5Ta0.5O3-δ. For both materials, a reversible temperature dependent phase transition (non-centrosymmetric to symmetric) is observed in the Raman spectrum in the region 533-583 K (260-310 °C); for Ba(Ti, Nb)O3, the onset is at 543 K (270 °C); and for Ba(Ti, Ta)O3, the onset is at 533 K (260 °C), which are comparable with 390-393 K (117-120 °C) for bulk BaTiO3. The crystal structure was resolved by examination of the powder x-ray diffraction and atomic pair distribution function (PDF) analysis of synchrotron total scattering data. It was postulated whether the structure adopted at the nanoscale was single or double perovskite. Double perovskites (A2B'B″O6) are characterized by the type and extent of cation ordering, which gives rise to higher symmetry crystal structures. PDF analysis was used to examine all likely candidate structures and to look for evidence of higher symmetry. The feasible phase space that evolves includes the ordered double perovskite structure Ba2(Ti, MV)O6 (M = Nb, Ta) Fm-3m, a disordered cubic structure, as a suitable high temperature analog, Ba(Ti, MV)O3Pm-3m, and an orthorhombic Ba(Ti, MV)O3Amm2, a room temperature structure that presents an unusually high level of lattice displacement, possibly due to octahedral tilting, and indication of a highly polarized crystal.
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Affiliation(s)
- Julien Lombardi
- The CUNY Energy Institute, City University of New York, Steinman Hall, 160 Convent Avenue, The City College of New York, New York, New York 10031, USA
- Department of Chemistry and Biochemistry, The City College of New York, 1024 Marshak, 160 Convent Avenue, New York, New York 10031, USA
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, New York, New York 10016, USA
| | - Long Yang
- School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
| | - Nasim Farahmand
- The CUNY Energy Institute, City University of New York, Steinman Hall, 160 Convent Avenue, The City College of New York, New York, New York 10031, USA
- Department of Chemistry and Biochemistry, The City College of New York, 1024 Marshak, 160 Convent Avenue, New York, New York 10031, USA
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, New York, New York 10016, USA
| | - Anthony Ruffino
- Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Ali Younes
- Department of Chemistry, Hunter College of the City University of New York, 695 Park Ave., New York, New York 10065, USA
| | - Jonathan E Spanier
- Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA
- Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104, USA
| | - Simon J L Billinge
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120th Street, New York, New York 10027, USA
| | - Stephen O'Brien
- The CUNY Energy Institute, City University of New York, Steinman Hall, 160 Convent Avenue, The City College of New York, New York, New York 10031, USA
- Department of Chemistry and Biochemistry, The City College of New York, 1024 Marshak, 160 Convent Avenue, New York, New York 10031, USA
- Ph.D. Program in Chemistry, The Graduate Center, The City University of New York, New York, New York 10016, USA
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Tan JH, Lin YY, Liu QJ, Liu FS, Liu ZT, Yang X. Structural, electronic, and optical properties of three types Ca 3N 2 from first-principles study. J Mol Model 2023; 30:9. [PMID: 38093144 DOI: 10.1007/s00894-023-05804-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 12/04/2023] [Indexed: 01/11/2024]
Abstract
CONTEXT To find the potential value of Ca3N2 in the field of optoelectronics, the physical properties of Ca3N2 will be analyzed. It can be concluded from the electronic properties that the Ca-N bonds of α-Ca3N2 are more stable than those of δ-Ca3N2 and ε-Ca3N2. The dielectric function, reflectivity function, and absorption function of three types of Ca3N2 were accurately calculated, and it was concluded that α-Ca3N2, δ-Ca3N2, and ε-Ca3N2 have greater transmittance for visible light and exhibit optical transparency in the near-infrared frequency domain. Combined with the high hardness, strong bonding, high melting point, and wear resistance of Ca3N2, Ca3N2 can be used as a new generation of window heat-resistant materials. The α-Ca3N2, δ-Ca3N2, and ε-Ca3N2 are indirect, direct, and indirect narrow bandgap compounds, respectively, that is, δ-Ca3N2 is more suitable for luminescent materials than α-Ca3N2 and ε-Ca3N2. α-Ca3N2 and δ-Ca3N2 have high reflective properties in the ultraviolet region and can be used as UV protective coatings. All three Ca3N2 materials can be used industrially to synthesize photovoltaic devices that operate in the ultraviolet region. METHODS Based on the first-principles of density functional theory calculations, the structures, electronic properties, and optical properties of α-Ca3N2, δ-Ca3N2, and ε-Ca3N2 were calculated. The calculation results show that although the α-Ca3N2, δ-Ca3N2, and ε-Ca3N2 have similar electronic structures, some phases have better properties in some aspects.
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Affiliation(s)
- Jia-Hao Tan
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Yong-Yi Lin
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Qi-Jun Liu
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Fu-Sheng Liu
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China
| | - Zheng-Tang Liu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an, 710072, People's Republic of China
| | - Xue Yang
- Bond and Band Engineering Group, School of Physical Science and Technology, Southwest Jiaotong University, Chengdu, 610031, People's Republic of China.
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Kalal S, Nayak S, Sahoo S, Joshi R, Choudhary RJ, Rawat R, Gupta M. Electronic correlations in epitaxial CrN thin film. Sci Rep 2023; 13:15994. [PMID: 37749139 PMCID: PMC10519984 DOI: 10.1038/s41598-023-42733-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 09/14/2023] [Indexed: 09/27/2023] Open
Abstract
Chromium nitride (CrN) spurred enormous interest due to its coupled magnetostructural and unique metal-insulator transition. The underneath electronic structure of CrN remains elusive. Herein, the electronic structure of epitaxial CrN thin film has been explored by employing resonant photoemission spectroscopy (RPES) and X-ray absorption near edge spectroscopy study in combination with the first-principles calculations. The RPES study indicates the presence of a charge-transfer screened 3[Formula: see text] ([Formula: see text]: hole in the N-2[Formula: see text]) and 3[Formula: see text] final-states in the valence band regime. The combined experimental electronic structure along with the orbital resolved electronic density of states from the first-principles calculations reveals the presence of Cr(3[Formula: see text])-N(2[Formula: see text]) hybridized (3[Formula: see text]) states between lower Hubbard (3[Formula: see text]) and upper Hubbard (3[Formula: see text]) bands with onsite Coulomb repulsion energy (U) and charge-transfer energy ([Formula: see text]) estimated as [Formula: see text] 4.5 and 3.6 eV, respectively. It verifies the participation of ligand (N-2[Formula: see text]) states in low energy charge fluctuations and provides concrete evidence for the charge-transfer ([Formula: see text]U) insulating nature of CrN thin film.
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Affiliation(s)
- Shailesh Kalal
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India
| | - Sanjay Nayak
- Department of Physics, Chemistry and Biology (IFM), Linköping University, 581 83, Linköping, Sweden
| | - Sophia Sahoo
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India
| | - Rajeev Joshi
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India
| | - Ram Janay Choudhary
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India
| | - Rajeev Rawat
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India
| | - Mukul Gupta
- UGC-DAE Consortium for Scientific Research, University Campus, Khandwa Road, Indore, 452 001, India.
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Tcakaev A, Rubrecht B, Facio JI, Zabolotnyy VB, Corredor LT, Folkers LC, Kochetkova E, Peixoto TRF, Kagerer P, Heinze S, Bentmann H, Green RJ, Gargiani P, Valvidares M, Weschke E, Haverkort MW, Reinert F, van den Brink J, Büchner B, Wolter AUB, Isaeva A, Hinkov V. Intermixing-Driven Surface and Bulk Ferromagnetism in the Quantum Anomalous Hall Candidate MnBi 6 Te 10. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2203239. [PMID: 36802132 PMCID: PMC10074120 DOI: 10.1002/advs.202203239] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/17/2023] [Indexed: 06/18/2023]
Abstract
The recent realizations of the quantum anomalous Hall effect (QAHE) in MnBi2 Te4 and MnBi4 Te7 benchmark the (MnBi2 Te4 )(Bi2 Te3 )n family as a promising hotbed for further QAHE improvements. The family owes its potential to its ferromagnetically (FM) ordered MnBi2 Te4 septuple layers (SLs). However, the QAHE realization is complicated in MnBi2 Te4 and MnBi4 Te7 due to the substantial antiferromagnetic (AFM) coupling between the SLs. An FM state, advantageous for the QAHE, can be stabilized by interlacing the SLs with an increasing number n of Bi2 Te3 quintuple layers (QLs). However, the mechanisms driving the FM state and the number of necessary QLs are not understood, and the surface magnetism remains obscure. Here, robust FM properties in MnBi6 Te10 (n = 2) with Tc ≈ 12 K are demonstrated and their origin is established in the Mn/Bi intermixing phenomenon by a combined experimental and theoretical study. The measurements reveal a magnetically intact surface with a large magnetic moment, and with FM properties similar to the bulk. This investigation thus consolidates the MnBi6 Te10 system as perspective for the QAHE at elevated temperatures.
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Affiliation(s)
- Abdul‐Vakhab Tcakaev
- Physikalisches Institut (EP‐IV)Universität WürzburgAm HublandD‐97074WürzburgGermany
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
| | - Bastian Rubrecht
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
| | - Jorge I. Facio
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
- Centro Atómico BarilocheInstituto de Nanociencia y Nanotecnología (CNEA‐CONICET) and Instituto Balseiro. Av. Bustillo 9500Bariloche8400Argentina
| | - Volodymyr B. Zabolotnyy
- Physikalisches Institut (EP‐IV)Universität WürzburgAm HublandD‐97074WürzburgGermany
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
| | - Laura T. Corredor
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
| | - Laura C. Folkers
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Institut für Festkörper‐ und MaterialphysikTechnische Universität DresdenD‐01062DresdenGermany
| | - Ekaterina Kochetkova
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
| | - Thiago R. F. Peixoto
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Physikalisches Institut (EP‐VII)Universität WürzburgAm HublandD‐97074WürzburgGermany
| | - Philipp Kagerer
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Physikalisches Institut (EP‐VII)Universität WürzburgAm HublandD‐97074WürzburgGermany
| | - Simon Heinze
- Institute for Theoretical PhysicsHeidelberg UniversityPhilosophenweg 1969120HeidelbergGermany
| | - Hendrik Bentmann
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Physikalisches Institut (EP‐VII)Universität WürzburgAm HublandD‐97074WürzburgGermany
| | - Robert J. Green
- Department of Physics and Astronomy and Stewart Blusson Quantum Matter InstituteUniversity of British ColumbiaVancouverBritish ColumbiaV6T 1Z4Canada
- Department of Physics and Engineering PhysicsUniversity of SaskatchewanSaskatoonSKS7N 5E2Canada
| | - Pierluigi Gargiani
- ALBA Synchrotron Light SourceE‐08290 Cerdanyola del VallèsBarcelonaSpain
| | - Manuel Valvidares
- ALBA Synchrotron Light SourceE‐08290 Cerdanyola del VallèsBarcelonaSpain
| | - Eugen Weschke
- Helmholtz‐Zentrum Berlin für Materialien und EnergieAlbert‐Einstein‐Straße 15D‐12489BerlinGermany
| | - Maurits W. Haverkort
- Institute for Theoretical PhysicsHeidelberg UniversityPhilosophenweg 1969120HeidelbergGermany
| | - Friedrich Reinert
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Physikalisches Institut (EP‐VII)Universität WürzburgAm HublandD‐97074WürzburgGermany
| | - Jeroen van den Brink
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
- Institut für Theoretische PhysikTechnische Universität DresdenD‐01062DresdenGermany
| | - Bernd Büchner
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
- Institut für Festkörper‐ und MaterialphysikTechnische Universität DresdenD‐01062DresdenGermany
| | - Anja U. B. Wolter
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
| | - Anna Isaeva
- Leibniz Institut für Festkörper‐ und Werkstoffforschung (IFW) DresdenHelmholtzstraße 20D‐01069DresdenGermany
- Van der Waals‐Zeeman InstituteDepartment of Physics and AstronomyUniversity of AmsterdamScience Park 904Amsterdam1098 XHThe Netherlands
| | - Vladimir Hinkov
- Physikalisches Institut (EP‐IV)Universität WürzburgAm HublandD‐97074WürzburgGermany
- Würzburg‐Dresden Cluster of Excellence ct.qmatGermany
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Ji Y, Liu P, Huang Y. First-principles screening of transition metal doped anatase TiO 2(101) surfaces for the electrocatalytic nitrogen reduction. Phys Chem Chem Phys 2023; 25:5827-5835. [PMID: 36745429 DOI: 10.1039/d2cp04635k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The electrocatalytic nitrogen reduction reaction (eNRR) has been attracting intensive scientific attention as a potential alternative to the industrial Haber-Bosch process for ammonia production. Although many materials have been investigated, optimal catalysts for the reaction remain to be found. In this work, we performed the theoretical screening of 3d-5d transition metal doped anatase TiO2 for the eNRR. The most favorable doping site of each transition metal on the (101) surface was located. We found that the doping of transition metals promotes the formation of oxygen vacancies which are beneficial for the reaction. The scaling relations between the energies of the key intermediates were investigated. Using a machine learning algorithm (SVM), we identified two adsorption modes for the end-on adsorbed *HNN, which exhibited different scaling relations with *NH2. From a two-step process, we screened out several candidates, among which Au and Ta were proposed to be the most efficient dopants. Electronic structure analysis reveals that they can efficiently lower the energy of the intermediates. These results should be helpful for the design of more efficient TiO2-based catalysts for the eNRR.
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Affiliation(s)
- Yongfei Ji
- School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, Guangdong, P. R. China.
| | - Paiyong Liu
- School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, Guangdong, P. R. China.
| | - Yungan Huang
- School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, Guangdong, P. R. China.
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9
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Kazim S, Mastrippolito D, Moras P, Jugovac M, Klimczuk T, Ali M, Ottaviano L, Gunnella R. Synchrotron radiation photoemission spectroscopy of the oxygen modified CrCl 3 surface. Phys Chem Chem Phys 2023; 25:3806-3814. [PMID: 36645158 DOI: 10.1039/d2cp04586a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We investigate the experimentally challenging CrCl3 surface by photon energy dependent photoemission (PE). The core and valence electrons after cleavage of a single crystal, either in a ultra-high vacuum (UHV) or in air, are studied by keeping the samples at 150 °C, aiming at confirming the atomic composition with respect to the expected bulk atomic structure. A common spectroscopic denominator revealed by data is the presence of a stable, but only partially ordered Cl-O-Cr surface. The electronic core levels (Cl 2p, Cr 2p and 3p), the latter ones of cumbersome component determination, allowed us to quantify the electron charge transfer to the Cr atom as a net result of this modification and the increased exchange interaction between metal and ligand atoms. In particular, the analysis of multiplet components by the CMT4XPS code evidenced the charge transfer to be favored, and similarly the reduced crystal field due to the established polarization field. Though it is often claimed that a significant amount of Cl and Cr atomic vacancies has to be included, such a possibility can be excluded on the basis of the sign and the importance of the shift in the binding energy of core level electrons. The present methodological approach can be of great impact to quantify the structure of ordered sub-oxide phases occurring in mono or bi-layer Cr trihalides.
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Affiliation(s)
- S Kazim
- School of Science and Technology Physics Section University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, MC, Italy.
| | - D Mastrippolito
- Dipartimento di Scienze Fisiche e Chimiche (DSFC), Università degli Studi dell'Aquila, Via Vetoio 10, 67100 L'Aquila, Italy
| | - P Moras
- Istituto di Struttura della Materia-CNR (ISM-CNR), S.S. 14, Km 163,5, 34149 Trieste, Italy
| | - M Jugovac
- Istituto di Struttura della Materia-CNR (ISM-CNR), S.S. 14, Km 163,5, 34149 Trieste, Italy
| | - T Klimczuk
- Faculty of Applied Physics and Mathematics, and Advanced Materials Centre, Gdansk University of Technology, ul. Narutowicza 11/12, 80-233 Gdansk, Poland
| | - M Ali
- Dipartimento di Scienze Fisiche e Chimiche (DSFC), Università degli Studi dell'Aquila, Via Vetoio 10, 67100 L'Aquila, Italy.,Department of Physics, Division of Science and Technology, University of Education Lahore, Jauharabad Campus, Pakistan
| | - L Ottaviano
- Dipartimento di Scienze Fisiche e Chimiche (DSFC), Università degli Studi dell'Aquila, Via Vetoio 10, 67100 L'Aquila, Italy.,CNR-SPIN UoS L' Aquila, Via Vetoio 10, 67100 L'Aquila, Italy
| | - R Gunnella
- School of Science and Technology Physics Section University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, MC, Italy. .,INFN-Sez. Perugia, Via Pascoli Perugia, Italy
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10
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Higashi K, Yamaguchi T, Takahashi Y, Hariki A. Charge-transfer effect in Fe 2 pcore-level x-ray photoemission spectra of trivalent Fe oxides: LDA + DMFT study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:375602. [PMID: 35793685 DOI: 10.1088/1361-648x/ac7f18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Motivated by recent hard x-ray photoemission spectroscopy (XPS) experiment for trivalent Fe oxides Sr2FeMoO6(ferrimagnetic correlated metal) and LaFeO3(antiferromagnetic Mott insulator) (Phuyalet al2021J. Phys. Chem.C12511249-56), we present a theoretical analysis of the Fe 2pcore-level spectra using a computational method based on local density approximation combined with dynamical mean-field theory. We find that a nonlocal screening (NLS) effect in the XPS final states is crucial for interpreting the experimental XPS result of both the Fe oxides. A close relationship between the NLS feature in core-level spectra and a long-range magnetic ordering is emphasized.
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Affiliation(s)
- Keisuke Higashi
- Department of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Tatsuya Yamaguchi
- Department of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Yoshihiro Takahashi
- Department of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
| | - Atsushi Hariki
- Department of Physics and Electronics, Graduate School of Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531, Japan
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11
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Abbasi P, Barone MR, de la Paz Cruz-Jáuregui M, Valdespino-Padilla D, Paik H, Kim T, Kornblum L, Schlom DG, Pascal TA, Fenning DP. Ferroelectric Modulation of Surface Electronic States in BaTiO 3 for Enhanced Hydrogen Evolution Activity. NANO LETTERS 2022; 22:4276-4284. [PMID: 35500055 DOI: 10.1021/acs.nanolett.2c00047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Ferroelectric nanomaterials offer the promise of switchable electronic properties at the surface, with implications for photo- and electrocatalysis. Studies to date on the effect of ferroelectric surfaces in electrocatalysis have been primarily limited to nanoparticle systems where complex interfaces arise. Here, we use MBE-grown epitaxial BaTiO3 thin films with atomically sharp interfaces as model surfaces to demonstrate the effect of ferroelectric polarization on the electronic structure, intermediate binding energy, and electrochemical activity toward the hydrogen evolution reaction (HER). Surface spectroscopy and ab initio DFT+U calculations of the well-defined (001) surfaces indicate that an upward polarized surface reduces the work function relative to downward polarization and leads to a smaller HER barrier, in agreement with the higher activity observed experimentally. Employing ferroelectric polarization to create multiple adsorbate interactions over a single electrocatalytic surface, as demonstrated in this work, may offer new opportunities for nanoscale catalysis design beyond traditional descriptors.
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Affiliation(s)
- Pedram Abbasi
- Department of NanoEngineering, University of California San Diego, La Jolla, California 92093, United States
| | - Matthew R Barone
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Ma de la Paz Cruz-Jáuregui
- Centro de Nanociencias y Nanotecnología (CNyN)-Universidad Nacional Autónoma de México (UNAM) Km 107, Carretera Tijuana-Ensenada Ensenada B.C., C.P 22800, Mexico
| | - Duilio Valdespino-Padilla
- Centro de Nanociencias y Nanotecnología (CNyN)-Universidad Nacional Autónoma de México (UNAM) Km 107, Carretera Tijuana-Ensenada Ensenada B.C., C.P 22800, Mexico
- Universidad Autónoma de Baja California (UABC), Km 107, Carretera Tijuana-Ensenada Ensenada B.C., C.P 22800, Mexico
| | - Hanjong Paik
- Platform for the Accelerated Realization, Analysis & Discovery of Interface Materials (PARADIM), Cornell University, Ithaca, New York 14853, United States
| | - Taewoo Kim
- Chemical Engineering Program, Department of Nanoengineering, University of California San Diego, La Jolla, California 92093, United States
| | - Lior Kornblum
- Andrew & Erna Viterbi Department of Electrical & Computer Engineering, Technion─Israel Institute of Technology, Haifa 32000-03, Israel
- The Nancy & Stephen Grand Technion Energy Program, Technion─Israel Institute of Technology, Haifa 32000-03, Israel
| | - Darrell G Schlom
- Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, United States
- Kavli Institute at Cornell for Nanoscale Science, Ithaca, New York 14853, United States
- Leibniz-Institut für Kristallzüchtung, Max-Born-Straße 2, 12489 Berlin, Germany
| | - Tod A Pascal
- Department of NanoEngineering, University of California San Diego, La Jolla, California 92093, United States
| | - David P Fenning
- Department of NanoEngineering, University of California San Diego, La Jolla, California 92093, United States
- Chemical Engineering Program, Department of Nanoengineering, University of California San Diego, La Jolla, California 92093, United States
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12
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Characterization of V2O3 Nanoscale Thin Films Prepared by DC Magnetron Sputtering Technique. COATINGS 2022. [DOI: 10.3390/coatings12050649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Vanadium sesquioxide V2O3, a transition metal oxide, is an important metal transition insulator due to its potential applications in novel electronic and memory devices. V2O3 thin films of thickness around 230 nm were grown on Si/SiO2/Ti/Pt substrates at deposition temperature of 723 K in a controlled Ar:O2 atmosphere of 35:2.5 sccm employing Direct Current (DC) magnetron sputtering. X-ray diffraction studies confirmed single phase of the material stabilized in corundum rhombohedral R3¯C phase. X-ray photoelectron spectroscopic results revealed chemical oxidation states are of V3+ and O2− and have nearly stochiometric elemental compositions in the films. Magnetization studies down to 10 K predicts a canted antiferromagnetic transition around 55 K. Out of 7 expected Raman active modes (2A1g + 5Eg), two A1g Raman active modes at 242 and 500 cm−1 were observed at ambient R3¯C phase. Temperature dependent Raman spectroscopic studies carried out from 80 to 300 K identified a monoclinic to rhombohedral phase transition at ~143 K.
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13
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Wu PC, Wei CC, Zhong Q, Ho SZ, Liou YD, Liu YC, Chiu CC, Tzeng WY, Chang KE, Chang YW, Zheng J, Chang CF, Tu CM, Chen TM, Luo CW, Huang R, Duan CG, Chen YC, Kuo CY, Yang JC. Twisted oxide lateral homostructures with conjunction tunability. Nat Commun 2022; 13:2565. [PMID: 35538081 PMCID: PMC9090740 DOI: 10.1038/s41467-022-30321-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 04/13/2022] [Indexed: 11/28/2022] Open
Abstract
Epitaxial growth is of significant importance over the past decades, given it has been the key process of modern technology for delivering high-quality thin films. For conventional heteroepitaxy, the selection of proper single crystal substrates not only facilitates the integration of different materials but also fulfills interface and strain engineering upon a wide spectrum of functionalities. Nevertheless, the lattice structure, regularity and crystalline orientation are determined once a specific substrate is chosen. Here, we reveal the growth of twisted oxide lateral homostructure with controllable in-plane conjunctions. The twisted lateral homostructures with atomically sharp interfaces can be composed of epitaxial "blocks" with different crystalline orientations, ferroic orders and phases. We further demonstrate that this approach is universal for fabricating various complex systems, in which the unconventional physical properties can be artificially manipulated. Our results establish an efficient pathway towards twisted lateral homostructures, adding additional degrees of freedom to design epitaxial films.
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Affiliation(s)
- Ping-Chun Wu
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chia-Chun Wei
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Qilan Zhong
- Key Laboratory of Polar Materials and Devices (MOE) and Department of Electronics, East China Normal University, 200241, Shanghai, China
| | - Sheng-Zhu Ho
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Yi-De Liou
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Yu-Chen Liu
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chun-Chien Chiu
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Wen-Yen Tzeng
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Kuo-En Chang
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Yao-Wen Chang
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Junding Zheng
- Key Laboratory of Polar Materials and Devices (MOE) and Department of Electronics, East China Normal University, 200241, Shanghai, China
| | - Chun-Fu Chang
- Max-Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany
| | - Chien-Ming Tu
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
| | - Tse-Ming Chen
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chih-Wei Luo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Rong Huang
- Key Laboratory of Polar Materials and Devices (MOE) and Department of Electronics, East China Normal University, 200241, Shanghai, China
| | - Chun-Gang Duan
- Key Laboratory of Polar Materials and Devices (MOE) and Department of Electronics, East China Normal University, 200241, Shanghai, China
| | - Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chang-Yang Kuo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- National Synchrotron Radiation Research Center, Hsinchu, 30076, Taiwan
| | - Jan-Chi Yang
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan.
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, 70101, Taiwan.
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14
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Kuo CY, Liou YD, Hu Z, Liao SC, Tsai HM, Fu HW, Hua CY, Chen YC, Lin HJ, Tanaka A, Chen CT, Yang JC, Chang CF. Photonic-Crafting of Non-Volatile and Rewritable Antiferromagnetic Spin Textures with Drastic Difference in Electrical Conductivity. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200610. [PMID: 35312103 DOI: 10.1002/adma.202200610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/15/2022] [Indexed: 06/14/2023]
Abstract
Antiferromagnetic spintronics is an emerging field of non-volatile data storage and information processing. The zero net magnetization and zero stray fields of antiferromagnetic materials eliminate interference between neighbor units, leading to high-density memory integrations. However, this invisible magnetic character at the same time also poses a great challenge in controlling and detecting magnetic states in antiferromagnets. Here, two antiferromagnetic spin states close in energy in strained BiFeO3 thin films at room temperature are discovered. It can be reversibly switched between these two non-volatile antiferromagnetic states by a moderate magnetic field and a non-contact optical approach. Importantly, the conductivity of the areas with each antiferromagnetic textures is drastically different. It is conclusively demonstrated the capability of optical writing and electrical reading of these newly discovered bistable antiferromagnetic states in the BiFeO3 thin films.
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Affiliation(s)
- Chang-Yang Kuo
- Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, 30010, Taiwan
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Yi-De Liou
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, 70101, Taiwan
| | - Zhiwei Hu
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden, 01187, Germany
| | - Sheng-Chieh Liao
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden, 01187, Germany
| | - Huang-Ming Tsai
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Huang-Wen Fu
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Chih-Yu Hua
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Yi-Chun Chen
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, 70101, Taiwan
| | - Hong-Ji Lin
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Arata Tanaka
- Department of Quantum Matter, ADSM, Hiroshima University, Higashi-Hiroshima, 739-8530, Japan
| | - Chien-Te Chen
- National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30076, Taiwan
| | - Jan-Chi Yang
- Department of Physics, National Cheng Kung University, Tainan, 70101, Taiwan
- Center for Quantum Frontiers of Research & Technology (QFort), National Cheng Kung University, Tainan, 70101, Taiwan
| | - Chun-Fu Chang
- Max-Planck Institute for Chemical Physics of Solids, Nöthnitzer Str. 40, Dresden, 01187, Germany
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15
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Ohkubo I, Mori T. Rational Design of 3d Transition-Metal Compounds for Thermoelectric Properties by Using Periodic Trends in Electron-Correlation Modulation. J Am Chem Soc 2022; 144:3590-3602. [PMID: 35170313 DOI: 10.1021/jacs.1c12520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electronic structures in solid-state transition-metal compounds can be represented by two parameters: the charge-transfer energy (Δ), which is the energy difference between the p-band of an anion and an upper Hubbard band contributed by transition-metal d-orbitals, and the onsite Coulomb repulsion energy (U), which represents the energy difference between lower and upper Hubbard bands composed of split d-orbitals in transition metals. These parameters can facilitate the classification of various types of electronic structures. In this study, the dependences of anion species (N3-, P3-, As3-, O2-, S2-, Se2-, Te2-, F-, Cl-, Br-, and I-) on Δ and U of 566 different binary and ternary 3d transition-metal compounds were investigated using ionic-model calculations. We were able to identify the systematic chemical trends in the variations in Δ and U values with the anion species of 11 different families of 3d transition-metal compounds in a comprehensive manner. The effective use of Δ-U diagrams given here, to facilitate the discovery and development of functional compounds, was demonstrated on thermoelectric compounds by classifying the thermoelectric properties of 3d transition-metal compounds and by predicting unrealized high-performance thermoelectric compounds.
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Affiliation(s)
- Isao Ohkubo
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Takao Mori
- International Center for Materials Nanoarchitectonics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.,Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573, Japan
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16
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Kong S, Lu M, Yan S, Zou Z. High-valence chromium accelerated interface electron transfer for water oxidation. Dalton Trans 2022; 51:16890-16897. [DOI: 10.1039/d2dt02908a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High-valence Cr ions at the interface between an alloy core and a reconstruction layer shell served as powerful electron acceptors, accelerating the electron transfer by means of the exchange effect of the Ni–O–Cr configuration.
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Affiliation(s)
- Shaoxi Kong
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22, Hankou Road, Nanjing, Jiangsu 210093, P. R. China
| | - Mengfei Lu
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22, Hankou Road, Nanjing, Jiangsu 210093, P. R. China
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nano Technology, School of Physics, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
| | - Shicheng Yan
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22, Hankou Road, Nanjing, Jiangsu 210093, P. R. China
| | - Zhigang Zou
- Collaborative Innovation Center of Advanced Microstructures, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, Nanjing University, No. 22, Hankou Road, Nanjing, Jiangsu 210093, P. R. China
- National Laboratory of Solid State Microstructures, Jiangsu Key Laboratory for Nano Technology, School of Physics, Nanjing University, No. 22 Hankou Road, Nanjing, Jiangsu 210093, P. R. China
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17
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Kanno S, Tada T, Utsumi T, Nakamura K, Hosono H. Electronic Correlation Strength of Inorganic Electrides from First Principles. J Phys Chem Lett 2021; 12:12020-12025. [PMID: 34898221 DOI: 10.1021/acs.jpclett.1c03637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Strongly correlated electron systems, generally recognized as d- and f-electron systems, have attracted attention as a platform for the emergence of exotic properties such as high-Tc superconductivity. However, correlated electron behaviors have been recently observed in a group of novel materials, electrides, in which s-electrons are confined in subnanometer-sized spaces. Here, we present a trend of electronic correlation of electrides by evaluating the electronic correlation strength obtained from model parameters characterizing effective Hamiltonians of 19 electrides from first principles. The calculated strengths vary in the order 0D ≫ 1D > 2D ∼ 3D electrides, which corresponds to experimental trends, and exceed 10 (a measure for the emergence of exotic properties) in all of the 0D and some of the 1D electrides. We also found the electronic correlation depends on the cation species surrounding the s-electrons. The results indicate that low-dimensional electrides will be new research targets for studies of strongly correlated electron systems.
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Affiliation(s)
- Shu Kanno
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Tomofumi Tada
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Takeru Utsumi
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
| | - Kazuma Nakamura
- Quantum Physics Section, Department of Basic Sciences, Kyushu Institute of Technology, 1-1 Sensui-cho, Tobata, Kitakyushu, Fukuoka 804-8550, Japan
| | - Hideo Hosono
- Materials Research Center for Element Strategy, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan
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18
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Farahmand N, McGinn CK, Zhang Q, Gai Z, Kymissis I, O'Brien S. Magnetic and dielectric property control in the multivalent nanoscale perovskite Eu 0.5Ba 0.5TiO 3. NANOSCALE 2021; 13:10365-10384. [PMID: 33988208 DOI: 10.1039/d1nr00588j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
We report nanoscale Eu0.5Ba0.5TiO3, a multiferroic in the bulk and candidate in the search to quantify the electric dipole moment of the electron. Eu0.5Ba0.5TiO3, in the form of nanoparticles and other nanostructures is interesting for nanocomposite integration, biomedical imaging and fundamental research, based upon the prospect of polarizability, f-orbital magnetism and tunable optical/radio luminescence. We developed a [non-hydrolytic]sol-[H2O-activated]gel route, derived from in-house metallic Ba(s)/Eu(s) alkoxide precursors and Ti{(OCH(CH3)2}4. Two distinct nanoscale compounds of Ba:Ti:Eu with the parent perovskite crystal structure were produced, with variable dielectric, magnetic and optical properties, based on altering the oxidizing/reducing conditions. Eu0.5Ba0.5TiO3 prepared under air/O2 atmospheres produced a spherical core-shell nanostructure (30-35 nm), with perovskite Eu0.5Ba0.5TiO3 nanocrystal core-insulating oxide shell layer (∼3 nm), presumed a pre-pyrochlore layer abundant with Eu3+. Fluorescence spectroscopy shows a high intensity 5D0→7F2 transition at 622 nm and strong red fluorescence. The core/shell structure demonstrated excellent capacitive properties: assembly into dielectric thin films gave low conductivity (2133 GΩ mm-1) and an extremely stable, low loss permittivity of εeff∼25 over a wide frequency range (tan δ < 0.01, 100 kHz-2 MHz). Eu0.5Ba0.5TiO3 prepared under H2/argon produced more irregular shaped nanocrystals (20-25) nm, with a thin film permittivity around 4 times greater (εeff 101, tan δ < 0.05, 10 kHz-2 MHz, σ∼59.54 kΩ mm-1). Field-cooled magnetization values of 0.025 emu g-1 for EBTO-Air and 0.84 emu g-1 for EBTO-Argon were observed. X-ray photoelectron spectroscopy analysis reveals a complex interplay of EuII/III/TiIII/IV configurations which contribute to the observed ferroic and fluorescence behavior.
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Affiliation(s)
- Nasim Farahmand
- The CUNY Energy Institute, City University of New York, Steinman Hall, 160 Convent Avenue, The City College of New York, New York, NY 10031, USA.
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19
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Istomin SY, Lyskov NV, Mazo GN, Antipov EV. Electrode materials based on complex d-metal oxides for symmetrical solid oxide fuel cells. RUSSIAN CHEMICAL REVIEWS 2021. [DOI: 10.1070/rcr4979] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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20
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Kalam K, Rammula R, Ritslaid P, Käämbre T, Link J, Stern R, Vinuesa G, Dueñas S, Castán H, Tamm A, Kukli K. Atomic layer deposited nanolaminates of zirconium oxide and manganese oxide from manganese(III)acetylacetonate and ozone. NANOTECHNOLOGY 2021; 32:335703. [PMID: 33962408 DOI: 10.1088/1361-6528/abfee9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Atomic layer deposition method was used to grow thin films consisting of ZrO2and MnOxlayers. Magnetic and electric properties were studied of films deposited at 300 °C. Some deposition characteristics of the manganese(III)acetylacetonate and ozone process were investigated, such as the dependence of growth rate on the deposition temperature and film crystallinity. All films were partly crystalline in their as-deposited state. Zirconium oxide contained cubic and tetragonal phases of ZrO2, while the manganese oxide was shown to consist of cubic Mn2O3and tetragonal Mn3O4phases. All the films exhibited nonlinear saturative magnetization with hysteresis, as well as resistive switching characteristics.
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Affiliation(s)
- Kristjan Kalam
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
| | - Raul Rammula
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
| | - Peeter Ritslaid
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
| | - Tanel Käämbre
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
| | - Joosep Link
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Raivo Stern
- National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia
| | - Guillermo Vinuesa
- Department of Electronics, University of Valladolid, Paseo Belén 15, E-47011 Valladolid, Spain
| | - Salvador Dueñas
- Department of Electronics, University of Valladolid, Paseo Belén 15, E-47011 Valladolid, Spain
| | - Helena Castán
- Department of Electronics, University of Valladolid, Paseo Belén 15, E-47011 Valladolid, Spain
| | - Aile Tamm
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
| | - Kaupo Kukli
- Institute of Physics, University of Tartu, W. Ostwaldi tn 1, 50411 Tartu, Estonia
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21
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Woicik JC, Weiland C, Rumaiz AK, Brumbach MT, Ablett JM, Shirley EL, Kas JJ, Rehr JJ. Core hole processes in x-ray absorption and photoemission by resonant Auger-electron spectroscopy and first-principles theory. PHYSICAL REVIEW. B 2020; 101:10.1103/physrevb.101.245105. [PMID: 34409241 PMCID: PMC8370031 DOI: 10.1103/physrevb.101.245105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Electron-core hole interactions are critical for proper interpretation of core-level spectroscopies commonly used as analytical tools in materials science. Here we utilize resonant Auger-electron spectroscopy to uniquely identify exciton, shake, and charge-transfer processes that result from the sudden creation of the core hole in both x-ray-absorption and photoemission spectra. These effects are captured for the transition-metal compounds SrTiO3 and MoS2 by fully ab initio, combined real-time cumulant, and Bethe-Salpeter equation approaches to account for core hole dynamics and screening. Atomic charges and excited-state electron-density fluctuations reflect materials' solid-state electronic structure, loss of translational symmetry around the core hole, and breakdown of the sudden approximation. They also demonstrate competition between long- and short-range screening in a solid.
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Affiliation(s)
- J C Woicik
- Material Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - C Weiland
- Material Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A K Rumaiz
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - M T Brumbach
- Materials Characterization Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - J M Ablett
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, 91192 Gif-sur-Yvette Cedex, France
| | - E L Shirley
- Sensor Science Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J J Kas
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - J J Rehr
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
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22
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Woicik JC, Weiland C, Jaye C, Fischer DA, Rumaiz AK, Shirley EL, Kas JJ, Rehr JJ. Charge-transfer satellites and chemical bonding in photoemission and x-ray absorption of SrTiO 3 and rutile TiO 2: Experiment and first-principles theory with general application to spectroscopic analysis. PHYSICAL REVIEW. B 2020; 101:10.1103/physrevb.101.245119. [PMID: 34409240 PMCID: PMC8370030 DOI: 10.1103/physrevb.101.245119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
First-principles, real-time-cumulant, and Bethe-Salpeter-equation calculations fully capture the detailed satellite structure that occurs in response to the sudden creation of the core hole in both photoemission and x-ray absorption spectra of the transition-metal compounds SrTiO3 and rutile TiO2. Analysis of the excited-state, real-space charge-density fluctuations betrays the physical nature of these many electron excitations that are shown to reflect the materials' solid-state electronic structure and chemical bonding. This first-principles development of the cumulant-based core hole spectral function is generally applicable to other systems and should become a standard tool for all similar spectroscopic analysis going beyond the quasiparticle physics of the photoelectric effect.
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Affiliation(s)
- J C Woicik
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - C Weiland
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - C Jaye
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - D A Fischer
- Materials Measurement Science Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - A K Rumaiz
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - E L Shirley
- Sensor Science Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - J J Kas
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - J J Rehr
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
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23
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Franceschi G, Kraushofer F, Meier M, Parkinson GS, Schmid M, Diebold U, Riva M. A Model System for Photocatalysis: Ti-Doped α-Fe 2O 3(11̅02) Single-Crystalline Films. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2020; 32:3753-3764. [PMID: 32421058 PMCID: PMC7222102 DOI: 10.1021/acs.chemmater.9b04908] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 04/08/2020] [Indexed: 06/11/2023]
Abstract
Hematite (α-Fe2O3) is one of the most investigated anode materials for photoelectrochemical water splitting. Its efficiency improves by doping with Ti, but the underlying mechanisms are not understood. One hurdle is separating the influence of doping on conductivity, surface states, and morphology, which all affect performance. To address this complexity, one needs well-defined model systems. We build such a model system by growing single-crystalline, atomically flat Ti-doped α-Fe2O3(11̅02) films by pulsed laser deposition (PLD). We characterize their surfaces, combining in situ scanning tunneling microscopy (STM) with density functional theory (DFT), and reveal how dilute Ti impurities modify the atomic-scale structure of the surface as a function of the oxygen chemical potential and Ti content. Ti preferentially substitutes subsurface Fe and causes a local restructuring of the topmost surface layers. Based on the experimental quantification of Ti-induced surface modifications and the structural model we have established, we propose a strategy that can be used to separate the effects of Ti-induced modifications to the surface atomic and electronic structures and bulk conductivity on the reactivity of Ti-doped hematite.
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Affiliation(s)
- Giada Franceschi
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
| | - Florian Kraushofer
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
| | - Matthias Meier
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
- Faculty
of Physics and Center for Computational Materials Science, University of Vienna, Sensengasse 8, 1090 Wien, Austria
| | - Gareth S. Parkinson
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
| | - Michael Schmid
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
| | - Ulrike Diebold
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
| | - Michele Riva
- Institute
of Applied Physics, TU Wien, Wiedner Hauptstraβe 8-10/E134, 1040 Wien, Austria
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24
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Liu WR, Pao CW, Yu DW, Chin YY, Wu WB, Lin HJ, Haw SC, Chu CH, Chao TY, Hsu HC, Chen JM, Hsu CH, Hsieh WF, Chen CT. Defect induced ferromagnetic ordering in epitaxial Zn 0.95Mn 0.05O films on sapphire (0 0 0 1). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:485708. [PMID: 31489845 DOI: 10.1088/1361-648x/ab3b71] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the influence of Mn dopant on magnetic properties of Zn0.95Mn0.05O (ZMO)/Al2O3(0 0 0 1) hetero-epitaxial systems grown by using pulsed-laser deposition. The room temperature (RT) intrinsic ferromagnetic (FM) ordering verified by superconducting quantum interference device magnetometer and x-ray magnetic circular dichroism spectrum of Mn L 2,3 edges is ascribed to the substitutional Mn atoms in the Zn site of ZnO. Mn in ZMO has a tetrahedral local symmetry instead of the octahedral symmetry of MnO, after verifying the absence of the Mn-related impurities or clusters in ZMO epitaxial film by Mn K-edge and Zn K-edge x-ray absorption spectroscopy spectrum, as well as the analysis of long-range structural ordering on Renninger scan of forbidden (0 0 0 5) reflection in x-ray diffraction, transmission electron microscopy and Raman spectrum. Comparison of x-ray absorption spectra of ZMO with those of ZnO epilayers at O K-, Zn K-, and L 3-edges indicates that the substitution of the Zn site with Mn enhances the charge-transfer (CT) transition and the presence of Zn vacancies (VZn) also dominate the photoluminescence (PL) spectrum, implying that the formation of numerous VZn defects plays an important role in activating FM interactions. The strong CT effect and the existence of high-density VZn suggest that the intrinsic RT FM ordering of insulating ZMO is a result of the formation of the bound magnetic polarons (BMPs) that interact with each other via intermediate magnetic impurities.
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Affiliation(s)
- Wei-Rein Liu
- Scientific Research Division, National Synchrotron Radiation Research Center, Hsinchu 30076, Taiwan
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25
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Zhang J, Cui R, Gao C, Bian L, Pu Y, Zhu X, Li X, Huang W. Cation-Modulated HER and OER Activities of Hierarchical VOOH Hollow Architectures for High-Efficiency and Stable Overall Water Splitting. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1904688. [PMID: 31544337 DOI: 10.1002/smll.201904688] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 09/07/2019] [Indexed: 06/10/2023]
Abstract
Atom-scale modulation of electronic regulation in nonprecious-based electrocatalysts is promising for efficient catalytic activities. Here, hierarchically hollow VOOH nanostructures are rationally constructed by partial iron substitution and systematically investigated for electrocatalytic water splitting. Benefiting from the hierarchically stable scaffold configuration, highly electrochemically active surface area, the synergistic effect of the active metal atoms, and optimal adsorption energies, the 3% Fe (mole ratio) substituted electrocatalyst (VOOH-3Fe) exhibits a low overpotential of 90 and 195 mV at 10 mA cm-2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media, respectively, superior than the other samples with a different substituted ratio. To the best of current knowledge, 195 mV overpotential at 10 mA cm-2 is the best value reported for V or Fe (oxy)hydroxide-based OER catalysts. Moreover, the electrolytic cell employing the VOOH-3Fe electrode as both the cathode and anode exhibits a cell voltage of 0.30 V at 10 mA cm-2 with a remarkable stability over 60 h. This work heralds a new pathway to design efficient bifunctional catalysts toward overall water splitting.
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Affiliation(s)
- Jian Zhang
- New Energy Technology Engineering Lab of Jiangsu Province, School of Science, Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Renjie Cui
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Chencheng Gao
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Linyi Bian
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Yong Pu
- New Energy Technology Engineering Lab of Jiangsu Province, School of Science, Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Xinbao Zhu
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, 210037, P. R. China
| | - Xing'ao Li
- New Energy Technology Engineering Lab of Jiangsu Province, School of Science, Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
| | - Wei Huang
- Key Laboratory for Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing University of Posts & Telecommunications (NUPT), Nanjing, 210023, P. R. China
- Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an, 710072, Shaanxi, P. R. China
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26
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Aiura Y, Ozawa K, Tezuka Y, Minohara M, Samizo A, Bando K, Kumigashira H, Mase K. In-gap state generated by La-on-Sr substitutional defects within the bulk of SrTiO 3. Phys Chem Chem Phys 2019; 21:14646-14653. [PMID: 31215560 DOI: 10.1039/c9cp02307k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Local distortion in the conduction pathway has a significant influence on the conducting properties of oxides. The electronic states induced in the band gap of SrTiO3 by La doping were investigated using photoemission spectroscopy (PES) and soft X-ray emission spectroscopy (SXES); moreover, the local distortion in the conduction pathway was examined using extended X-ray absorption fine structure (EXAFS). An itinerant state and a localized state were observed as a metallic state and an in-gap state, respectively, in the PES spectra and as inelastic peaks in the SXES spectra. This implied that the itinerant state and the in-gap state coexisted within the bulk. From EXAFS results, it was observed that La doped into SrTiO3 substituted Sr and locally distorted the conduction pathway. The results showed that some electrons doped by La-on-Sr substitution are trapped/localized by the local distortion in the conduction pathway, whereas the remaining doped electrons itinerate in the pristine conduction pathway with no distortion.
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Affiliation(s)
- Yoshihiro Aiura
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
| | - Kenichi Ozawa
- Department of Chemistry, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan
| | - Yasuhisa Tezuka
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Aomori 036-8561, Japan
| | - Makoto Minohara
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan.
| | - Akane Samizo
- Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8568, Japan. and Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Katsushika, Tokyo 125-8585, Japan
| | - Kyoko Bando
- Nanomaterials Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8565, Japan
| | - Hiroshi Kumigashira
- Photon Factory, Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan and Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8578, Japan
| | - Kazuhiko Mase
- Photon Factory, Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan and SOKENDAI (The Graduate University for Advanced Studies), Tsukuba, Ibaraki 305-0801, Japan
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27
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Li Y, Zheng YS, Zhu YA, Sui ZJ, Zhou XG, Chen D, Yuan WK. BEEF-vdW+U method applied to perovskites: thermodynamic, structural, electronic, and magnetic properties. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:145901. [PMID: 30641492 DOI: 10.1088/1361-648x/aafe3e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The recently developed BEEF-vdW exchange-correlation method provides a reasonably reliable description of both long-range van der Waals interactions and short-range covalent bonding between molecules and surfaces. However, this method still suffers from the excessive electron delocalization that is connected with the self-interaction error and, consequently, the calculated chemical and physical properties such as formation energy and band gap deviate markedly from the experimental values, especially when strongly correlated systems are under investigation. In this contribution, BEEF-vdW+U calculations have been performed to study the thermodynamic, structural, electronic, and magnetic properties of La-based perovskites. An effective interaction parameter [Formula: see text] and an energy adjustment [Formula: see text] are determined simultaneously by a mixing GGA and GGA+U method, where the enthalpy or Gibbs free energy of formation of oxides containing a transition metal in different oxidation states are fitted to available experimental data. The [Formula: see text] is found to have its origin in the fact that the GGA+U method gives rise to the offsets in the total energy that include not only the desired physical correction but also an arbitrary contribution. Calculated results indicate that the BEEF-vdW method provides a more accurate description of the bonding in the O2 molecule than the PBE method and has generally smaller [Formula: see text] values for the 3d-block transition metals, thereby giving rise to band gaps and magnetic moments that are in better agreement with the experimentally measured values.
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Affiliation(s)
- Yang Li
- UNILAB, State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, People's Republic of China
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28
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Wang W, Wu M, Han P, Liu Y, He L, Huang Q, Wang J, Yan W, Fu L, Wu Y. Understanding the Behavior and Mechanism of Oxygen-Deficient Anatase TiO 2 toward Sodium Storage. ACS APPLIED MATERIALS & INTERFACES 2019; 11:3061-3069. [PMID: 30566318 DOI: 10.1021/acsami.8b19288] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
TiO2 has drawn increasing research attention as negative electrode material in sodium ion battery because of its natural abundance, low cost, nontoxicity, and facile preparation. Despite tremendous studies carried out, the sodium storage mechanism is still under discussion, and the electronic and local structures of TiO2 during sodiation/desodiation process are not well understood either. Herein, we reported a mechanism study of graphene-supported oxygen-deficient anatase TiO2 nanotubes (nanowires) as the negative electrode material for sodium ion batteries. Different from the previous reports, the insertion/extraction of Na+ ions leads to almost no changes of titanium valence state but there is a charge redistribution of O 2p orbitals which alters the hybridization between O 2p and Ti 3d states, suggested by the combined electrochemical and X-ray spectroscopic study. Both the electronic and local structures of TiO2 during the reversible sodiation/desodiation process are revealed from the Ti L-edge and O K-edge spectra. This detailed study would shed light on the material design and structural optimization of TiO2 as energy storage material in different systems.
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Affiliation(s)
- Weigang Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
| | - Meng Wu
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics , Xiamen University , Xiamen , 361005 , China
| | - Peng Han
- Capital Normal University , 05 West Third Ring Road North , Haidian District, Beijing 100048 , China
| | - Yu Liu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
| | - Liang He
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
| | - Qinghong Huang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
| | - Jing Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
| | - Wensheng Yan
- National Synchrotron Radiation Laboratory , University of Science and Technology of China , Hefei, Anhui 230029 , China
| | - Lijun Fu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
- South China Normal University , No. 55, West Zhongshan Road , Tianhe District, Guangzhou, Guangdong 510631 , China
| | - Yuping Wu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Energy Science and Engineering and Institute of Advanced Materials , Nanjing Tech University , No. 30, Puzhu Road (S) , Nanjing, Jiangsu 211800 , China
- South China Normal University , No. 55, West Zhongshan Road , Tianhe District, Guangzhou, Guangdong 510631 , China
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29
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Complex strain evolution of polar and magnetic order in multiferroic BiFeO 3 thin films. Nat Commun 2018; 9:3764. [PMID: 30242162 PMCID: PMC6155110 DOI: 10.1038/s41467-018-06190-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 08/20/2018] [Indexed: 11/08/2022] Open
Abstract
Electric-field control of magnetism requires deterministic control of the magnetic order and understanding of the magnetoelectric coupling in multiferroics like BiFeO3 and EuTiO3. Despite this critical need, there are few studies on the strain evolution of magnetic order in BiFeO3 films. Here, in (110)-oriented BiFeO3 films, we reveal that while the polarization structure remains relatively unaffected, strain can continuously tune the orientation of the antiferromagnetic-spin axis across a wide angular space, resulting in an unexpected deviation of the classical perpendicular relationship between the antiferromagnetic axis and the polarization. Calculations suggest that this evolution arises from a competition between the Dzyaloshinskii-Moriya interaction and single-ion anisotropy wherein the former dominates at small strains and the two are comparable at large strains. Finally, strong coupling between the BiFeO3 and the ferromagnet Co0.9Fe0.1 exists such that the magnetic anisotropy of the ferromagnet can be effectively controlled by engineering the orientation of the antiferromagnetic-spin axis.
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30
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Mathieu C, Gonzalez S, Lubin C, Copie O, Feyer V, Schneider CM, Barrett N. High-temperature 2D Fermi surface of SrTiO3
studied by energy-filtered PEEM. SURF INTERFACE ANAL 2018. [DOI: 10.1002/sia.6533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Claire Mathieu
- SPEC, CEA, CNRS; Université Paris-Saclay, CEA Saclay; Gif-sur-Yvette Cedex France
| | - Sara Gonzalez
- SPEC, CEA, CNRS; Université Paris-Saclay, CEA Saclay; Gif-sur-Yvette Cedex France
- BaDElPh beamline; Elettra-Sincrotrone Trieste; S.S. 14 km 163.5 in AREA Science Park Basovizza I-34149 Trieste Italy
| | - Christophe Lubin
- SPEC, CEA, CNRS; Université Paris-Saclay, CEA Saclay; Gif-sur-Yvette Cedex France
| | - Olivier Copie
- Institut Jean Lamour; UMR 7198 CNRS/Université de Lorraine; Vandoeuvre-lès-Nancy France
| | - Vitaliy Feyer
- Peter Grünberg Institute (PGI-6); JARA-FIT, Research Center Jülich; Jülich Germany
- NanoESCA beamline; Elettra-Sincrotrone Trieste; S.S. 14 km 163.5 in AREA Science Park Basovizza I-34149 Trieste Italy
| | - Claus M. Schneider
- Peter Grünberg Institute (PGI-6); JARA-FIT, Research Center Jülich; Jülich Germany
| | - Nick Barrett
- SPEC, CEA, CNRS; Université Paris-Saclay, CEA Saclay; Gif-sur-Yvette Cedex France
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31
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Wu M, Xin HL, Wang JO, Li XJ, Yuan XB, Zeng H, Zheng JC, Wang HQ. Investigation of the multiplet features of SrTiO 3 in X-ray absorption spectra based on configuration interaction calculations. JOURNAL OF SYNCHROTRON RADIATION 2018; 25:777-784. [PMID: 29714188 DOI: 10.1107/s160057751800423x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 03/12/2018] [Indexed: 06/08/2023]
Abstract
Synchrotron-based L2,3-edge absorption spectra show strong sensitivities to the local electronic structure and chemical environment. However, detailed physical information cannot be extracted easily without computational aids. Here, using the experimental Ti L2,3-edges absorption spectrum of SrTiO3 as a fingerprint and considering full multiplet effects, calculations yield different energy parameters characterizing local ground state properties. The peak splitting and intensity ratios of the L3 and L2 set of peaks are carefully analyzed quantitatively, giving rise to a small hybridization energy around 1.2 eV, and the different hybridization energy values reported in the literature are further addressed. Finally, absorption spectra with different linearly polarized photons under various tetragonal crystal fields are investigated, revealing a non-linear orbital-lattice interaction, and a theoretical guidance for material engineering of SrTiO3-based thin films and heterostructures is offered. Detailed analysis of spectrum shifts with different tetragonal crystal fields suggests that the eg crystal field splitting is a necessary parameter for a thorough analysis of the spectra, even though it is not relevant for the ground state properties.
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Affiliation(s)
- M Wu
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - Houlin L Xin
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - J O Wang
- Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - X J Li
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - X B Yuan
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - H Zeng
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - J C Zheng
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
| | - H Q Wang
- Fujian Provincial Key Laboratory of Semiconductors and Applications, Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Department of Physics, Xiamen University, Xiamen 361005, People's Republic of China
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32
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Wu M, Zheng JC, Wang HQ. Investigation of the multiplet structures and crystal field effects of a TiO6 3d
1 cluster based on configuration interaction calculations. J Appl Crystallogr 2017. [DOI: 10.1107/s160057671700334x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Configuration interaction cluster calculation can effectively reproduce the experimentally measured Ti L
23-edge absorption spectrum for the TiO6 cluster LaTiO3. A further investigation of the hybridization strength and charge-transfer energy effects on the multiplet structures suggests that LaTiO3 should be classified as an intermediate state between the charge-transfer and Mott–Hubbard regimes. Detailed temperature-dependent simulations of absorption spectra support the lifting of Ti t
2g
orbital degeneracy and crystal field splitting. The spin–orbit coupling scenario is ruled out, even though 3d spin–orbit coupling can reproduce the experimental spectrum without including temperature. A combined polarization- and crystal-field-splitting-dependent analysis indicates asymmetric ΔCF–orbital interactions for the TiO6 cluster [Ti3+:3d
1(t
2g
1)], different from the orbital–lattice interactions reported for the NiO6 cluster [Ni3+:3d
7(t
2g
6
eg
1)]. The orbital polarization is defined in terms of the normalized electron occupancies in orbitals with xy and xz(yz) symmetries, and nearly complete orbital polarization (more than 75%) is observed, indicating strongly reduced orbital fluctuations due to the correlation effects. This is consistent with the density of states for titanates based on local density approximation plus dynamical mean-field theory calculations.
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Abstract
The strong coupling between antiferromagnetism and ferroelectricity at room temperature found in BiFeO3 generates high expectations for the design and development of technological devices with novel functionalities. However, the multi-domain nature of the material tends to nullify the properties of interest and complicates the thorough understanding of the mechanisms that are responsible for those properties. Here we report the realization of a BiFeO3 material in thin film form with single-domain behaviour in both its magnetism and ferroelectricity: the entire film shows its antiferromagnetic axis aligned along the crystallographic b axis and its ferroelectric polarization along the c axis. With this we are able to reveal that the canted ferromagnetic moment due to the Dzyaloshinskii–Moriya interaction is parallel to the a axis. Furthermore, by fabricating a Co/BiFeO3 heterostructure, we demonstrate that the ferromagnetic moment of the Co film does couple directly to the canted moment of BiFeO3. The coupling of ferroelectric and antiferromagnetic order in BiFeO3 makes it appealing for applications however the presence of domain structure acts to undermine this potential. Here, the authors demonstrate BiFeO3 thin films with a single domain of electrical polarization and canted antiferromagnetic order.
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35
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Abstract
The Mott insulator in correlated electron systems arises from classical Coulomb repulsion between carriers to provide a powerful force for electron localization. Turning such an insulator into a metal, the so-called Mott transition, is commonly achieved by "bandwidth" control or "band filling." However, both mechanisms deviate from the original concept of Mott, which attributes such a transition to the screening of Coulomb potential and associated lattice contraction. Here, we report a pressure-induced isostructural Mott transition in cubic perovskite PbCrO3. At the transition pressure of ∼3 GPa, PbCrO3 exhibits significant collapse in both lattice volume and Coulomb potential. Concurrent with the collapse, it transforms from a hybrid multiferroic insulator to a metal. For the first time to our knowledge, these findings validate the scenario conceived by Mott. Close to the Mott criticality at ∼300 K, fluctuations of the lattice and charge give rise to elastic anomalies and Laudau critical behaviors resembling the classic liquid-gas transition. The anomalously large lattice volume and Coulomb potential in the low-pressure insulating phase are largely associated with the ferroelectric distortion, which is substantially suppressed at high pressures, leading to the first-order phase transition without symmetry breaking.
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36
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Chen D, Chen C, Baiyee ZM, Shao Z, Ciucci F. Nonstoichiometric Oxides as Low-Cost and Highly-Efficient Oxygen Reduction/Evolution Catalysts for Low-Temperature Electrochemical Devices. Chem Rev 2015; 115:9869-921. [DOI: 10.1021/acs.chemrev.5b00073] [Citation(s) in RCA: 666] [Impact Index Per Article: 74.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Dengjie Chen
- Department
of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Chi Chen
- Department
of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zarah Medina Baiyee
- Department
of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Zongping Shao
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry & Chemical Engineering, Nanjing Tech University, No. 5 Xin Mofan Road, Nanjing 210009, China
- Department
of Chemical Engineering, Curtin University, Perth, Western Australia 6845, Australia
| | - Francesco Ciucci
- Department
of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
- Department
of Chemical and Biomolecular Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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37
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Xu Z, Joshi YV, Raman S, Kitchin JR. Accurate electronic and chemical properties of 3d transition metal oxides using a calculated linear response U and a DFT + U(V) method. J Chem Phys 2015; 142:144701. [DOI: 10.1063/1.4916823] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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38
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A large family of filled skutterudites stabilized by electron count. Nat Commun 2015; 6:6489. [DOI: 10.1038/ncomms7489] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 02/03/2015] [Indexed: 11/09/2022] Open
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39
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40
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Mossanek RJO, Domínguez-Cañizares G, Gutiérrez A, Abbate M, Díaz-Fernández D, Soriano L. Effects of Ni vacancies and crystallite size on the O 1s and Ni 2p x-ray absorption spectra of nanocrystalline NiO. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:495506. [PMID: 24214889 DOI: 10.1088/0953-8984/25/49/495506] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have studied the electronic structure of nanocrystalline NiO thin films, grown by radio-frequency magnetron sputtering under different experimental conditions, using x-ray absorption spectroscopy. The O 1s and Ni 2p spectra showed distinct changes as a function of O2 content in the plasma, which were reproduced with cluster model calculations. These changes are attributed to the incrementing of the surface contribution due to a decrease of the crystallite size as the O2 content in the plasma increases, and to the presence of induced nickel vacancies. Thus, the changes in the electronic structure can be related to the modification of structural and transport properties of these nanocrystalline films.
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Affiliation(s)
- R J O Mossanek
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba-PR, Brazil
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41
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Sautet P, Bocquet ML. Imaging Molecules with the Scanning Tunneling Microscope: A Theoretical Interpretation of Benzene on Platinum. Isr J Chem 2013. [DOI: 10.1002/ijch.199600009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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42
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Borgatti F, Park C, Herpers A, Offi F, Egoavil R, Yamashita Y, Yang A, Kobata M, Kobayashi K, Verbeeck J, Panaccione G, Dittmann R. Chemical insight into electroforming of resistive switching manganite heterostructures. NANOSCALE 2013; 5:3954-3960. [PMID: 23535767 DOI: 10.1039/c3nr00106g] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have investigated the role of the electroforming process in the establishment of resistive switching behaviour for Pt/Ti/Pr0.5Ca0.5MnO3/SrRuO3 layered heterostructures (Pt/Ti/PCMO/SRO) acting as non-volatile Resistance Random Access Memories (RRAMs). Electron spectroscopy measurements demonstrate that the higher resistance state resulting from electroforming of as-prepared devices is strictly correlated with the oxidation of the top electrode Ti layer through field-induced electromigration of oxygen ions. Conversely, PCMO exhibits oxygen depletion and downward change of the chemical potential for both resistive states. Impedance spectroscopy analysis, supported by the detailed knowledge of these effects, provides an accurate model description of the device resistive behaviour. The main contributions to the change of resistance from the as-prepared (low resistance) to the electroformed (high resistance) states are respectively due to reduced PCMO at the boundary with the Ti electrode and to the formation of an anisotropic n-p junction between the Ti and the PCMO layers.
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Affiliation(s)
- Francesco Borgatti
- CNR--Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), via P. Gobetti 101, I-40129 Bologna, Italy.
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43
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Da Pieve F, Di Matteo S, Rangel T, Giantomassi M, Lamoen D, Rignanese GM, Gonze X. Origin of magnetism and quasiparticles properties in Cr-doped TiO2. PHYSICAL REVIEW LETTERS 2013; 110:136402. [PMID: 23581348 DOI: 10.1103/physrevlett.110.136402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Indexed: 06/02/2023]
Abstract
Combining the local spin density approximation (LSDA)+U and an analysis of superexchange interactions beyond density functional theory, we describe the magnetic ground state of Cr-doped TiO2, an intensively studied and debated dilute magnetic oxide. In parallel, we correct our LSDA+U (+ superexchange) ground state through GW corrections (GW@LSDA+U) that reproduce the position of the impurity states and the band gaps in satisfying agreement with experiments. Because of the different topological coordinations of Cr-Cr bonds in the ground states of rutile and anatase, superexchange interactions induce either ferromagnetic or antiferromagnetic couplings of Cr ions. In Cr-doped anatase, this interaction leads to a new mechanism which stabilizes a (nonrobust) ferromagnetic ground state, in keeping with experimental evidence, without the need to invoke F-center exchange. The interplay between structural defects and vacancies in contributing to the superexchange is also unveiled.
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Affiliation(s)
- F Da Pieve
- EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
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44
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Yang JC, He Q, Suresha SJ, Kuo CY, Peng CY, Haislmaier RC, Motyka MA, Sheng G, Adamo C, Lin HJ, Hu Z, Chang L, Tjeng LH, Arenholz E, Podraza NJ, Bernhagen M, Uecker R, Schlom DG, Gopalan V, Chen LQ, Chen CT, Ramesh R, Chu YH. Orthorhombic BiFeO3. PHYSICAL REVIEW LETTERS 2012; 109:247606. [PMID: 23368382 DOI: 10.1103/physrevlett.109.247606] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 09/07/2012] [Indexed: 05/12/2023]
Abstract
A new orthorhombic phase of the multiferroic BiFeO3 has been created via strain engineering by growing it on a NdScO(3)(110)(o) substrate. The tensile-strained orthorhombic BiFeO3 phase is ferroelectric and antiferromagnetic at room temperature. A combination of nonlinear optical second harmonic generation and piezoresponse force microscopy revealed that the ferroelectric polarization in the orthorhombic phase is along the in-plane {110}(pc) directions. In addition, the corresponding rotation of the antiferromagnetic axis in this new phase was observed using x-ray linear dichroism.
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Affiliation(s)
- J C Yang
- Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan
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45
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Kyeremateng NA, Hornebecq V, Martinez H, Knauth P, Djenizian T. Electrochemical Fabrication and Properties of Highly Ordered Fe-Doped TiO2Nanotubes. Chemphyschem 2012; 13:3707-13. [DOI: 10.1002/cphc.201200406] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Indexed: 11/08/2022]
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46
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Liao P, Keith JA, Carter EA. Water Oxidation on Pure and Doped Hematite (0001) Surfaces: Prediction of Co and Ni as Effective Dopants for Electrocatalysis. J Am Chem Soc 2012; 134:13296-309. [DOI: 10.1021/ja301567f] [Citation(s) in RCA: 418] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Peilin Liao
- Departments of †Chemistry and ‡Mechanical and Aerospace Engineering, and §Program in Applied
and Computational
Mathematics and Gerhard R. Andlinger Center for Energy and the Environment, Princeton University, Princeton, New
Jersey 08544-5263, United States
| | - John A. Keith
- Departments of †Chemistry and ‡Mechanical and Aerospace Engineering, and §Program in Applied
and Computational
Mathematics and Gerhard R. Andlinger Center for Energy and the Environment, Princeton University, Princeton, New
Jersey 08544-5263, United States
| | - Emily A. Carter
- Departments of †Chemistry and ‡Mechanical and Aerospace Engineering, and §Program in Applied
and Computational
Mathematics and Gerhard R. Andlinger Center for Energy and the Environment, Princeton University, Princeton, New
Jersey 08544-5263, United States
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47
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Weber C, O'Regan DD, Hine NDM, Payne MC, Kotliar G, Littlewood PB. Vanadium dioxide: a Peierls-Mott insulator stable against disorder. PHYSICAL REVIEW LETTERS 2012; 108:256402. [PMID: 23004627 DOI: 10.1103/physrevlett.108.256402] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Indexed: 06/01/2023]
Abstract
Vanadium dioxide undergoes a first order metal-insulator transition at 340 K. In this Letter, we develop and carry out state-of-the-art linear scaling density-functional theory calculations refined with nonlocal dynamical mean-field theory. We identify a complex mechanism, a Peierls-assisted orbital selection Mott instability, which is responsible for the insulating M(1) phase, and which furthermore survives a moderate degree of disorder.
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Affiliation(s)
- Cédric Weber
- Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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48
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Khoa Le T, Flahaut D, Foix D, Blanc S, Hung Nguyen HK, Xuan Huynh TK, Martinez H. Study of surface fluorination of photocatalytic TiO2 by thermal shock method. J SOLID STATE CHEM 2012. [DOI: 10.1016/j.jssc.2012.01.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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49
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Chen H, Navea JG, Young MA, Grassian VH. Heterogeneous Photochemistry of Trace Atmospheric Gases with Components of Mineral Dust Aerosol. J Phys Chem A 2011; 115:490-9. [DOI: 10.1021/jp110164j] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Haihan Chen
- Departments of Chemical and Biochemical Engineering and Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Juan G. Navea
- Departments of Chemical and Biochemical Engineering and Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Mark A. Young
- Departments of Chemical and Biochemical Engineering and Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
| | - Vicki H. Grassian
- Departments of Chemical and Biochemical Engineering and Chemistry, The University of Iowa, Iowa City, Iowa 52242, United States
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50
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Okumura T, Fukutsuka T, Yanagihara A, Orikasa Y, Arai H, Ogumi Z, Uchimoto Y. Electronic and local structural changes with lithium-ion insertion in TiO2-B: X-ray absorption spectroscopy study. ACTA ACUST UNITED AC 2011. [DOI: 10.1039/c1jm11335f] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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