Fe57Mössbauer and x-ray magnetic circular dichroism study of magnetic compensation of the rare-earth sublattice inNd2−xHoxFe14Bcompounds

Abstract

We present here a study of the magnetic properties of the ${\mathrm{Nd}}_{2\ensuremath{-}x}{\mathrm{Ho}}_{x}{\mathrm{Fe}}_{14}\mathrm{B}$ series. The macroscopic properties of these compounds evolve continuously from those of ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ to those of ${\mathrm{Ho}}_{2}{\mathrm{Fe}}_{14}\mathrm{B}$ as Ho gradually replaces Nd. The system shows a compensation of the rare-earth sublattice magnetization for a critical concentration, ${x}_{c}=0.55$, that is reflected into the anomalous behavior of both macroscopic and microscopic magnetic probes. The combined analysis of magnetization, $^{57}\mathrm{Fe}$ M\"ossbauer spectroscopy and Fe $K$-edge x-ray magnetic circular dichroism (XMCD) measurements suggests that the origin of the anomalous magnetic behavior found at ${x}_{c}=0.55$ is mainly due to the Ho sublattice. Moreover, the analysis of the Fe $K$-edge XMCD signals reveal the presence of a rare-earth contribution, reflecting the coupling of the rare-earth and Fe magnetic moments, which can lead to the possibility of disentangling the magnetic behavior of both Fe and R atoms using a single absorption edge.