First-Principles Calculations of Crystal Field Parameters of Nd Ions Near Surfaces and Interfaces in Nd-Fe-B Magnets

Author

Tsuchiura, Hiroki ; Yoshioka, Takashi ; Novak, Petr

Author_Institution

Dept. of Appl. Phys., Tohoku Univ., Sendai, Japan

Volume

50

Issue

11

fYear

2014

fDate

Nov. 2014

Firstpage

1

Lastpage

4

Abstract

We study the local magnetic anisotropy due to Nd ions located around surfaces of Nd₂Fe₁₄B within the crystal field theory based on first-principles calculations. The Nd ions on the (001) surface exhibit A₂⁰ <; 0, that is, the in-plane anisotropy, as reported previously, but those on the (100) surface exhibit A₂⁰ > 0, which is consistent with the bulk c-axis uniaxial anisotropy. The physical origin of these conflicting local anisotropies can be understood from the 6p and 5d valence charge distributions realized in the Nd₂Fe₁₄B structure.

Keywords

ab initio calculations; boron alloys; crystal field interactions; iron alloys; magnetic anisotropy; neodymium alloys; permanent magnets; (001) surface; 5d valence charge distributions; 6p valence charge distributions; Nd ions; Nd-Fe-B magnets; Nd₂Fe₁₄B; bulk c-axis uniaxial anisotropy; crystal field parameters; crystal field theory; first-principles calculations; in-plane anisotropy; local magnetic anisotropy; Anisotropic magnetoresistance; Crystals; Ions; Iron; Perpendicular magnetic anisotropy; Slabs; Magnets; compounds; elements; materials; permanent magnets;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2014.2329294

Filename

6971475