# Magnetic moment of rare earth elements in R2Fe14B estimated with {\mu}^+SR

## TL;DR

This study uses muon spin rotation ({}^+SR) measurements combined with DFT calculations to estimate the magnetic moments of rare earth elements in R2Fe14B, providing insights into their ferromagnetic properties and temperature dependence.

## Contribution

It introduces a method to estimate rare earth magnetic moments in R2Fe14B using {}^+SR data and theoretical calculations, extending previous approaches.

## Key findings

- Estimated Nd moment at 5 K is 3.31 μ_B.
- M_R values in various R2Fe14B compounds agree with other methods.
- Ferromagnetic order persists above 600 K in Nd2Fe14B.

## Abstract

The ferromagnetic (FM) nature of Nd2Fe14B has been investigated with muon spin rotation and relaxation ({\mu}^+SR) measurements on an aligned, sintered plate-shaped sample. A clear muon spin precession frequency (f_{FM}) corresponding to the static internal FM field at the muon site showed an order parameter-like temperature dependence and disappeared above around 582 K (~T_C). This indicated that the implanted muons are static in the Nd2Fe14B lattice even at temperatures above around 600 K. Using the predicted muon site and local spin densities predicted by DFT calculations, the ordered Nd moment (M_{Nd}) was estimated to be 3.31 {\mu}_B at 5 K, when both M_{Fe} and M_{Nd} are parallel to the c-axis and M_{Fe} = 2.1 {\mu}_B. Furthermore, M_R in R2Fe14B with R = Y, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er, and Tm was estimated from f_{\mu} values reported in earlier {\mu}+SR work, using the FM structure proposed by neutron scattering and the same muon site and local spin density as in Nd2Fe14B. Such estimations yielded M_R values consistent with those obtained by the other methods.