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Title: Correlations in rare-earth transition-metal permanent magnets

Abstract

It is investigated how electron-electron correlations affect the intrinsic properties of rare-earth transition-metal magnets. Focusing on orbital moment and anisotropy, we perform model calculations for 3d-4f alloys and density-functional theory (DFT) calculations for NdCo{sub 5}. On an independent-electron level, the use of a single Slater determinant with broken spin symmetry introduces Hund's rule correlations, which govern the behavior of rare-earth ions and of alloys described by the local spin density approximation (LSDA) and LSDA + U approximations to DFT. By contrast, rare-earth ions in intermetallics involve configuration interactions between two or more Slater determinants and lead to phenomena such as spin-charge distribution. Analyzing DFT as a Legendre transformation and using Bethe's crystal-field theory, we show that the corresponding density functionals are very different from familiar LSDA-type expressions and outline the effect of spin-charge separation on the magnetocrystalline anisotropy.

Authors:
;  [1];  [2]
  1. Department of Physics and Astronomy and NCMN, University of Nebraska, Lincoln, Nebraska 68508 (United States)
  2. School of Basic Science, IIT Mandi, Mandi, Himachal Pradesh (India)
Publication Date:
OSTI Identifier:
22410039
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 117; Journal Issue: 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; APPROXIMATIONS; CHARGE DISTRIBUTION; COBALT; CONFIGURATION INTERACTION; CRYSTAL FIELD; DENSITY FUNCTIONAL METHOD; ELECTRON CORRELATION; ELECTRONS; INTERMETALLIC COMPOUNDS; NEODYMIUM; PERMANENT MAGNETS; SLATER METHOD; SPIN

Citation Formats

Skomski, R., E-mail: rskomski@neb.rr.com, Manchanda, P., and Kashyap, A. Correlations in rare-earth transition-metal permanent magnets. United States: N. p., 2015. Web. doi:10.1063/1.4917003.
Skomski, R., E-mail: rskomski@neb.rr.com, Manchanda, P., & Kashyap, A. Correlations in rare-earth transition-metal permanent magnets. United States. doi:10.1063/1.4917003.
Skomski, R., E-mail: rskomski@neb.rr.com, Manchanda, P., and Kashyap, A. Thu . "Correlations in rare-earth transition-metal permanent magnets". United States. doi:10.1063/1.4917003.
@article{osti_22410039,
title = {Correlations in rare-earth transition-metal permanent magnets},
author = {Skomski, R., E-mail: rskomski@neb.rr.com and Manchanda, P. and Kashyap, A.},
abstractNote = {It is investigated how electron-electron correlations affect the intrinsic properties of rare-earth transition-metal magnets. Focusing on orbital moment and anisotropy, we perform model calculations for 3d-4f alloys and density-functional theory (DFT) calculations for NdCo{sub 5}. On an independent-electron level, the use of a single Slater determinant with broken spin symmetry introduces Hund's rule correlations, which govern the behavior of rare-earth ions and of alloys described by the local spin density approximation (LSDA) and LSDA + U approximations to DFT. By contrast, rare-earth ions in intermetallics involve configuration interactions between two or more Slater determinants and lead to phenomena such as spin-charge distribution. Analyzing DFT as a Legendre transformation and using Bethe's crystal-field theory, we show that the corresponding density functionals are very different from familiar LSDA-type expressions and outline the effect of spin-charge separation on the magnetocrystalline anisotropy.},
doi = {10.1063/1.4917003},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 17,
volume = 117,
place = {United States},
year = {2015},
month = {5}
}