Magnetic moment of rare-earth elements in R2Fe14 B estimated with μ+SR

Abstract

The ferromagnetic (FM) nature of Nd2Fe14B has been investigated with muon spin rotation and relaxation (μ+SR) measurements on an aligned, sintered plate-shaped sample. A clear muon spin precession frequency (fFM) corresponding to the static internal FM field at the muon site showed an order parameter-like temperature dependence and disappeared above around 582 K (∼TC). This indicated that the implanted muons are static in the Nd2Fe14B lattice even at temperatures above around 600 K. Using the muon site and local spin densities predicted by DFT calculations, the ordered Nd moment (MNd) was estimated to be 3.31 μB at 5 K, when both MFe and MNd are parallel to the ĉ axis and MFe=2.1μB. Furthermore, MR in R2Fe14B with R=Y, Ce, Pr, Sm, Gd, Tb, Dy, Ho, Er, and Tm was estimated from fμ values reported in earlier μ+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 MR values consistent with those obtained by the other methods.