Determining anisotropy constants from a first-order magnetization process inTb2Fe17

Abstract

The critical parameters of a first-order magnetization process, ${H}_{\mathrm{cr}}$ and ${m}_{\mathrm{cr}}$, are used to determine the anisotropy constants ${K}_{1}$ and ${K}_{2}$ of ${\mathrm{Tb}}_{2}{\mathrm{Fe}}_{17}$ in the temperature range between 5 and $300\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Both anisotropy constants are proportional to the critical field ${H}_{\mathrm{cr}}$ (times spontaneous magnetization), whereas their ratio is independent of ${H}_{\mathrm{cr}}$ and depends solely on the dimensionless reduced critical magnetization ${m}_{\mathrm{cr}}$. The employed method of determining ${K}_{1}$ and ${K}_{2}$ is complementary to the classical Sucksmith--Thompson technique, which is inapplicable in the case of a first-order magnetization process.