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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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2
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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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Lehtola S, Manninen P, Hakala M, Hämäläinen K. Contraction of completeness-optimized basis sets: Application to ground-state electron momentum densities. J Chem Phys 2013; 138:044109. [DOI: 10.1063/1.4788635] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Susi Lehtola
- Department of Physics, University of Helsinki, P.O. Box 64, FI-00014 University of Helsinki, Finland.
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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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Koizumi A, Motoyama G, Kubo Y, Tanaka T, Itou M, Sakurai Y. f Electron contribution to the change of electronic structure in CeRu2Si2 with temperature: a Compton scattering study. PHYSICAL REVIEW LETTERS 2011; 106:136401. [PMID: 21517401 DOI: 10.1103/physrevlett.106.136401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Indexed: 05/30/2023]
Abstract
High resolution Compton profiles have been measured in the single crystal of CeRu(2)Si(2) above and below the Kondo temperature to elucidate the change of the Ce-4f electron from localized to itinerant states. Two-dimensional electron occupation number densities projected on the first Brillouin zone, which are obtained after a series of analyses, clearly specify the difference between itinerant and localized states. The contribution of Ce-4f electrons to the electronic structure is discussed by contrast with a band calculation.
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Affiliation(s)
- A Koizumi
- Graduate School of Material Science, University of Hyogo, Hyogo 678-1297, Japan
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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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