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Abstract
The redox process in a lithium-ion battery occurs when a conduction electron from the lithium anode is transferred to the redox orbital of the cathode. Understanding the nature of orbitals involved in anionic as well as cationic redox reactions is important for improving the capacity and energy density of Li-ion batteries. In this connection, we have obtained magnetic Compton profiles (MCPs) from the Li-rich cation-disordered rock-salt compound LixTi0.4Mn0.4O2 (LTMO). The MCPs, which involved the scattering of circularly polarized hard X-rays, are given by the momentum density of all the unpaired spins in the material. The net magnetic moment in the ground state can be extracted from the area under the MCP, along with a SQUID measurement. Our analysis gives insight into the role of Mn 3d magnetic electrons and O 2p holes in the magnetic redox properties of LTMO.
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Honer CJ, Prosniewski MJ, Putatunda A, Singh DJ. Properties of the antiferromagnetic selenite MnSeO 3 and its non-magnetic analogue ZnSnO 3 from first principles calculations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:405501. [PMID: 28703714 DOI: 10.1088/1361-648x/aa7f89] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report the properties of the antiferromagnetic selenite MnSeO3 and the non-magnetic analogue ZnSeO3, based on first principles calculations. These compounds are rare examples of ABO3 perovskites with a tetravalent A-site and a divalent B-site. The electronic structure is discussed in the context of the bonding and crystal structure. There is cross-gap hybridization between the O p states that form the valence bands of these compounds and the unoccupied p states of Se, reflecting the lone pair physics that leads to the strong off-centering of Se from the perovskite A-site. The G-type antiferromagnetism of MnSeO3 is a local moment in nature arising from high spin [Formula: see text] with short range interactions. Additionally, there is an interesting spin-dependent hybridization of Mn d and O p states analogous to that in colossal magnetoresistance manganites.
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Affiliation(s)
- C J Honer
- Department of Physics and Astronomy, University of Missouri, Columbia, MO 65211-7010, United States of America
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3
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Suzuki K, Barbiellini B, Orikasa Y, Go N, Sakurai H, Kaprzyk S, Itou M, Yamamoto K, Uchimoto Y, Wang YJ, Hafiz H, Bansil A, Sakurai Y. Extracting the redox orbitals in Li battery materials with high-resolution x-ray compton scattering spectroscopy. PHYSICAL REVIEW LETTERS 2015; 114:087401. [PMID: 25768779 DOI: 10.1103/physrevlett.114.087401] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Indexed: 06/04/2023]
Abstract
We present an incisive spectroscopic technique for directly probing redox orbitals based on bulk electron momentum density measurements via high-resolution x-ray Compton scattering. Application of our method to spinel Li_{x}Mn_{2}O_{4}, a lithium ion battery cathode material, is discussed. The orbital involved in the lithium insertion and extraction process is shown to mainly be the oxygen 2p orbital. Moreover, the manganese 3d states are shown to experience spatial delocalization involving 0.16±0.05 electrons per Mn site during the battery operation. Our analysis provides a clear understanding of the fundamental redox process involved in the working of a lithium ion battery.
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Affiliation(s)
- K Suzuki
- Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - B Barbiellini
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - Y Orikasa
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - N Go
- Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - H Sakurai
- Faculty of Science and Technology, Gunma University, Tenjin-cho, Kiryu, Gunma 376-8515, Japan
| | - S Kaprzyk
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
- Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, aleja Mickiewicza 30, 30-059 Krakow, Poland
| | - M Itou
- Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan
| | - K Yamamoto
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Y Uchimoto
- Graduate School of Human and Environmental Studies, Kyoto University, Yoshida-nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yung Jui Wang
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - H Hafiz
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - A Bansil
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
| | - Y Sakurai
- Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo, Sayo, Hyogo 679-5198, Japan
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4
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A Minimal tight-binding model for ferromagnetic canted bilayer manganites. Sci Rep 2014; 4:7512. [PMID: 25522737 PMCID: PMC4271262 DOI: 10.1038/srep07512] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 11/20/2014] [Indexed: 11/25/2022] Open
Abstract
Half-metallicity in materials has been a subject of extensive research due to its potential for applications in spintronics. Ferromagnetic manganites have been seen as a good candidate, and aside from a small minority-spin pocket observed in La2−2xSr1+2xMn2O7 (x = 0.38), transport measurements show that ferromagnetic manganites essentially behave like half metals. Here we develop robust tight-binding models to describe the electronic band structure of the majority as well as minority spin states of ferromagnetic, spin-canted antiferromagnetic, and fully antiferromagnetic bilayer manganites. Both the bilayer coupling between the MnO2 planes and the mixing of the |x2 − y2 > and |3z2 − r2 > Mn 3d orbitals play an important role in the subtle behavior of the bilayer splitting. Effects of kz dispersion are included.
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Ernsting D, Billington D, Haynes TD, Millichamp TE, Taylor JW, Duffy JA, Giblin SR, Dewhurst JK, Dugdale SB. Calculating electron momentum densities and Compton profiles using the linear tetrahedron method. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:495501. [PMID: 25390292 DOI: 10.1088/0953-8984/26/49/495501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A method for computing electron momentum densities and Compton profiles from ab initio calculations is presented. Reciprocal space is divided into optimally-shaped tetrahedra for interpolation, and the linear tetrahedron method is used to obtain the momentum density and its projections such as Compton profiles. Results are presented and evaluated against experimental data for Be, Cu, Ni, Fe3Pt, and YBa2Cu4O8, demonstrating the accuracy of our method in a wide variety of crystal structures.
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Affiliation(s)
- D Ernsting
- H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol, BS8 1TL, UK
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Deb A, Boron TT, Itou M, Sakurai Y, Mallah T, Pecoraro VL, Penner-Hahn JE. Understanding Spin Structure in Metallacrown Single-Molecule Magnets using Magnetic Compton Scattering. J Am Chem Soc 2014; 136:4889-92. [DOI: 10.1021/ja501452w] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Aniruddha Deb
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Thaddeus T. Boron
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Masayoshi Itou
- Japan Synchrotron
Radiation Research Institute (JASRI)/SPring-8, Sayo, Hyogo 679-5198, Japan
| | - Yoshiharu Sakurai
- Japan Synchrotron
Radiation Research Institute (JASRI)/SPring-8, Sayo, Hyogo 679-5198, Japan
| | - Talal Mallah
- Institut
de Chimie Moléculaire et des Matériaux d’Orsay,
CNRS, Université de Paris Sud, 91405 Orsay Cedex, France
| | - Vincent L. Pecoraro
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - James E. Penner-Hahn
- Department
of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
- Program
in Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
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Shinoda R, Itou M, Sakurai Y, Yamamoto H, Hirao N, Baba Y, Iwase A, Matsui T. Magnetic Compton scattering studies of magneto-dielectric Ba(Co 0.85Mn 0.15)O 3-δ. JOURNAL OF APPLIED PHYSICS 2013; 113:17E307. [PMID: 23653488 PMCID: PMC3637313 DOI: 10.1063/1.4799476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Accepted: 01/11/2013] [Indexed: 06/02/2023]
Abstract
We revealed that the Ba(Co0.85Mn0.15)O3-δ ceramic samples exhibited ferromagnetic-dielectric behavior below the magnetic transition temperature of about 35 K. The origin of their magnetic ordering was expected to super-exchange coupling of Co4+(d5)-O2--Mn4+(d3) with bonding angle of 180° and/or Mn4+(d3)-O2--Mn4+(d3) with bonding angle of 90°. The magnetic spin momentum estimated by the magnetic Compton profiles (MCP) of the samples had similar temperature dependence as that determined by the temperature dependence of magnetic moment by superconducting quantum interference device, which meant that the observed magnetic moments could be ascribed to the spin moment. The shapes of the MCPs of the samples were completely same regardless of the temperature measured. This result indicates that there are no changes of the momentum space distribution of spin density between ferromagnetic and paramagnetic states. So, this magnetic transition is simply caused by a thermal fluctuation of the spin.
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Arredondo Y, Vallejo E, Navarro O, Avignon M. Formation of spin-polarons in the ferromagnetic Kondo lattice model away from half-filling. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:335601. [PMID: 22836220 DOI: 10.1088/0953-8984/24/33/335601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Even though realistic one-dimensional experiments in the field of half-metallic semiconductors are not at hand yet, we are interested in the underlying fundamental physics. In this regard we study a one-dimensional ferromagnetic Kondo lattice model, a model in which a conduction band is coupled ferromagnetically to a background of localized d moments with coupling constant J(H), and investigate the T = 0 phase diagram as a function of the antiferromagnetic interaction J between the localized moments and the band-filling n, since it has been observed that doping of the compounds has led to formation of magnetic domains. We explore the spin-polaron formation by looking at the nearest-neighbour correlation functions in the spin and charge regimes for which we use the density matrix renormalization group method, which is a highly efficient method to investigate quasi-one-dimensional strongly correlated systems.
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Affiliation(s)
- Y Arredondo
- Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, 04510 México D.F., Mexico.
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Sahariya J, Tiwari S, Mund HS, Sarma S, Srinivasan A, Itou M, Sakurai Y, Ahuja BL. A magnetic Compton scattering study of Ga rich Co-Ni-Ga ferromagnetic shape memory alloys. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:386002. [PMID: 21900735 DOI: 10.1088/0953-8984/23/38/386002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The temperature dependent spin momentum densities of Co(1.8)NiGa(1.2) and Co(2)Ni(0.76)Ga(1.24) alloys have been measured using the magnetic Compton scattering technique. The individual contributions of constituents in the formation of the total spin moment are also calculated using Compton line shape analysis. The magnetic Compton data when compared with the magnetization data obtained using a vibrating sample magnetometer show a negligible orbital contribution. The spin moments deduced from the experimental Compton data are compared with the theoretical results obtained from the full potential linearized augmented plane wave method and are found to be in good agreement. The origin of the magnetism in both alloys is also described in terms of the e(g) and t(2g) contributions of Ni and Co.
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Affiliation(s)
- Jagrati Sahariya
- Department of Physics, University College of Science, M L Sukhadia University, Udaipur 313001, India
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Sakurai Y, Itou M, Barbiellini B, Mijnarends PE, Markiewicz RS, Kaprzyk S, Gillet JM, Wakimoto S, Fujita M, Basak S, Wang YJ, Al-Sawai W, Lin H, Bansil A, Yamada K. Imaging Doped Holes in a Cuprate Superconductor with High-Resolution Compton Scattering. Science 2011; 332:698-702. [DOI: 10.1126/science.1199391] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Ahmed A, Itou M, Xu S, Xu Z, Cao G, Sakurai Y, Penner-Hahn J, Deb A. Competing ferromagnetism and superconductivity on FeAs layers in EuFe2(As0.73P0.27)2. PHYSICAL REVIEW LETTERS 2010; 105:207003. [PMID: 21231257 DOI: 10.1103/physrevlett.105.207003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Indexed: 05/30/2023]
Abstract
We have measured the spin-polarized electron momentum density distributions of EuFe2(As0.73P0.27)2 by magnetic Compton scattering (MCS) measurements. For the first time, we show direct evidence of competing ferromagnetism and superconductivity (SC) on FeAs layers in this iron pnictide system. The MCS orbitalwise decomposition of the density distributions reveals that between 16 and 19 K, the spin-polarized Fe-3d character is enhanced (as the ferromagnetic character supersedes superconducting character), where the resistivity shows a maximum, reentrant SC-like peak, at 18 K. The spin polarization of the Fe-3d orbital, enhanced by ferromagnetic Eu ions, suppresses the SC around 18 K, while at other temperatures the system indeed exhibits SC where the Fe-3d spin polarization is suppressed or collapses.
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Affiliation(s)
- Aamir Ahmed
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Barbiellini B, Koizumi A, Mijnarends PE, Al-Sawai W, Lin H, Nagao T, Hirota K, Itou M, Sakurai Y, Bansil A. Role of oxygen electrons in the metal-insulator transition in the magnetoresistive oxide La2-2xSr1+2xMn2O7 probed by compton scattering. PHYSICAL REVIEW LETTERS 2009; 102:206402. [PMID: 19519045 DOI: 10.1103/physrevlett.102.206402] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Indexed: 05/27/2023]
Abstract
We have studied the [100]-[110] anisotropy of the Compton profile in the bilayer manganite. Quantitative agreement is found between theory and experiment with respect to the anisotropy in the two metallic phases (i.e., the low temperature ferromagnetic and the colossal magnetoresistant phase under a magnetic field of 7 T). Robust signatures of the metal-insulator transition are identified in the momentum density for the paramagnetic phase above the Curie temperature. We interpret our results as providing direct evidence for the transition from the metalliclike to the admixed ionic-covalent bonding accompanying the magnetic transition. The number of electrons involved in this phase transition is estimated. Our study demonstrates the sensitivity of the Compton scattering technique for identifying the number and type of electrons involved in the metal-insulator transition.
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Affiliation(s)
- B Barbiellini
- Physics Department, Northeastern University, Boston, Massachusetts 02115, USA
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Saniz R, Norman MR, Freeman AJ. Orbital mixing and nesting in the bilayer manganites La2-2xSr1+2xMn2O7. PHYSICAL REVIEW LETTERS 2008; 101:236402. [PMID: 19113571 DOI: 10.1103/physrevlett.101.236402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2008] [Indexed: 05/27/2023]
Abstract
A first principles study of La2-2xSr1+2xMn2O7 compounds for doping levels 0.3 < or = x < or = 0.5 shows that the low energy electronic structure of the majority spin carriers is determined by strong momentum-dependent interactions between the Mn eg dx2-y2 and d3z2-r2 orbitals, which, in addition to an x-dependent Jahn-Teller distortion, differ in the ferromagnetic and antiferromagnetic phases. The Fermi surface exhibits nesting behavior that is reflected by peaks in the static susceptibility, whose positions as a function of momentum have a nontrivial dependence on x.
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Affiliation(s)
- R Saniz
- Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
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Asaka T, Kimura T, Nagai T, Yu XZ, Kimoto K, Tokura Y, Matsui Y. Observation of magnetic ripple and nanowidth domains in a layered ferromagnet. PHYSICAL REVIEW LETTERS 2005; 95:227204. [PMID: 16384261 DOI: 10.1103/physrevlett.95.227204] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2005] [Indexed: 05/05/2023]
Abstract
We investigated ferromagnetic domain structures on nanometer to micrometer scale for single crystals of a layered ferromagnet, La(2-2x)Sr(1+2x)Mn2O7 (0.32 < or = x < or = 0.40), as functions of x and temperature by means of Lorentz electron microscopy. We have succeeded in observing the evolution of magnetic ripple structure, dynamically, related to a spin reorientation transition where the magnetization direction switches between parallel and perpendicular to the layers. Our high-resolution magnetic domain imaging revealed that the ripple state is characterized by the evolution of magnetic nanowidth domains.
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Affiliation(s)
- T Asaka
- High Voltage Electron Microscopy Station, National Institute for Materials Science, Tsukuba 305-0044, Japan
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Li Y, Montano PA, Mitchell JF, Barbiellini B, Mijnarends PE, Kaprzyk S, Bansil A. Temperature-dependent orbital degree of freedom of a bilayer manganite by magnetic compton scattering. PHYSICAL REVIEW LETTERS 2004; 93:207206. [PMID: 15600966 DOI: 10.1103/physrevlett.93.207206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2004] [Indexed: 05/24/2023]
Abstract
We have measured temperature-dependent magnetic Compton profiles (MCPs) from a single crystal of La1.2Sr1.8Mn2O7. The MCPs, which involved the scattering of circularly polarized x rays, are in general related to the momentum density of all the unpaired spins in the system. Nevertheless, we show that when the x-ray scattering vector lies along the [110] direction, the number of magnetic electrons of a specific symmetry, i.e., d electrons of x(2)-y(2) symmetry, yield a distinct signature in the MCP, allowing us to monitor substantial changes in the occupancy of the dx(2)(-y(2)) states over the investigated temperature range of 5-200 K. This study indicates that magnetic Compton scattering can provide a powerful window on the properties of specific magnetic electrons in complex materials.
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Affiliation(s)
- Yinwan Li
- Department of Physics, University of Illinois, Chicago, Illinois 60680, USA
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Manganites. ACTA ACUST UNITED AC 2004. [DOI: 10.1007/978-3-662-09298-9_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2023]
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Uzuhara S, Koizumi H, Miyaki S, Makoshi K. Ab initio cluster study of the local lattice instability in La2−2xSr1+2xMn2O7. Chem Phys Lett 2002. [DOI: 10.1016/s0009-2614(02)00555-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Miyaki S, Koizumi H, Makoshi K. Ab initio cluster study of the bilayer manganite La2−2xSr1+2xMn2O7. Chem Phys Lett 2001. [DOI: 10.1016/s0009-2614(01)01307-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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