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Title: Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides

Abstract

Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spin orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericitymore » and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low symmetry structures. As a result, through crystal field calculations we also illustrate the crystal field ground state 4f multiplets of light lanthanides.« less

Authors:
 [1];  [1];  [1]
  1. Ames Lab. and Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Lab., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1363631
Alternate Identifier(s):
OSTI ID: 1363807; OSTI ID: 1415240
Report Number(s):
IS-J-9278; IS-J-9217
Journal ID: ISSN 0304-8853; PII: S0304885317307631
Grant/Contract Number:
AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Magnetism and Magnetic Materials
Additional Journal Information:
Journal Volume: 441; Journal Issue: C; Journal ID: ISSN 0304-8853
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY

Citation Formats

Hackett, Timothy A., Baldwin, D. J., and Paudyal, Durga. Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides. United States: N. p., 2017. Web. doi:10.1016/j.jmmm.2017.05.019.
Hackett, Timothy A., Baldwin, D. J., & Paudyal, Durga. Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides. United States. doi:10.1016/j.jmmm.2017.05.019.
Hackett, Timothy A., Baldwin, D. J., and Paudyal, Durga. Wed . "Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides". United States. doi:10.1016/j.jmmm.2017.05.019. https://www.osti.gov/servlets/purl/1363631.
@article{osti_1363631,
title = {Electronic, magnetic, and magnetocrystalline anisotropy properties of light lanthanides},
author = {Hackett, Timothy A. and Baldwin, D. J. and Paudyal, Durga},
abstractNote = {Theoretical understanding of interactions between localized and mobile electrons and the crystal environment in light lanthanides is important because of their key role in much needed magnetic anisotropy in permanent magnet materials that have a great impact in automobile and wind turbine applications. We report electronic, magnetic, and magnetocrystalline properties of these basic light lanthanide elements studied from advanced density functional theory (DFT) calculations. We find that the inclusion of onsite 4f electron correlation and spin orbit coupling within the full-potential band structure is needed to understand the unique magnetocrystalline properties of these light lanthanides. The onsite electron correlation, spin orbit coupling, and full potential for the asphericity of charge densities must be taken into account for the proper treatment of 4f states. We find the variation of total energy as a function of lattice constants that indicate multiple structural phases in Ce contrasting to a single stable structure obtained in other light lanthanides. The 4f orbital magnetic moments are partially quenched as a result of crystalline electric field splitting that leads to magnetocrystalline anisotropy. The charge density plots have similar asphericity and environment in Pr and Nd indicating similar magnetic anisotropy. However, Ce and Sm show completely different asphericity and environment as both orbital moments are significantly quenched. In addition, the Fermi surface structures exemplified in Nd indicate structural stability and unravel a cause of anisotropy. The calculated magnetocrystalline anisotropy energy (MAE) reveals competing c-axis and in-plane anisotropies, and also predicts possibilities of unusual structural deformations in light lanthanides. The uniaxial magnetic anisotropy is obtained in the double hexagonal closed pack structures of the most of the light lanthanides, however, the anisotropy is reduced or turned to planar in the low symmetry structures. As a result, through crystal field calculations we also illustrate the crystal field ground state 4f multiplets of light lanthanides.},
doi = {10.1016/j.jmmm.2017.05.019},
journal = {Journal of Magnetism and Magnetic Materials},
number = C,
volume = 441,
place = {United States},
year = {Wed May 17 00:00:00 EDT 2017},
month = {Wed May 17 00:00:00 EDT 2017}
}

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