High performance magnetic material with Ce and La: an alternative to Nd-Fe-B magnet

TL;DR

This study explores Ce and La doping in R2Fe14B compounds, showing that Ce doping at specific sites can produce magnetic anisotropy comparable to Nd2Fe14B, offering a promising alternative for high-performance magnetic materials.

Contribution

It provides a detailed theoretical analysis of site-specific Ce and La doping effects on magnetic anisotropy and moments in R2Fe14B compounds, highlighting Ce's potential as a substitute for Nd.

Findings

Ce doping at 4f-site yields high magnetic anisotropy.

Ce2Fe14B has a maximum magnetic moment close to Nd2Fe14B.

Ce substitution can produce comparable magnetic properties to Nd-based magnets.

Abstract

A systematic study of magnetocrystalline anisotropy is performed for R(La/Ce/Nd)2Fe14B tetragonal compound with the site substitution mechanism. Theoretical calculation suggests the 50% doping with Ce at 4f-site can lead to competitive magnetic anisotropy to that of the champion magnet Nd2Fe14B. Electronic structure calculations are performed using the full-potential linearized augmented plane wave method by inclusion of the spin-orbit coupling and Hubbard (U) interaction in the calculation for the rare-earth elements to get the correct influence of the localized 4f orbitals. Detailed analysis of the magnetic moment and magnetic anisotropy change has been studied by individually inserting the La and Ce atoms at the two inequivalent sites (4g and 4f sites) of the 2-14-B tetragonal structure. Accurate prediction of the total magnetic moment with the orbital contribution in the 2-14-B structure shows the maximum moment for Ce2Fe14B (3.86 {\mu}B/f.u less) compared to Nd2Fe14B. Theoretical analysis confirms that regardless of the anti-parallel spin moment emerging in the Ce atom the complex structure of the Ce substituted compound at 4f-site gives the maximum anisotropy of 2.27 meV/cell with lowering the magnetic moment by 1.26 {\mu}B/f.u. compared to the Nd2Fe14B compound.