First-order field-induced magnetization transitions in single-crystal Nd2Fe14B

Abstract

Magnetization measurements in high‐pulsed magnetic fields have revealed the presence of magnetic anisotropy in the hard basal plane of a single crystal of Nd₂Fe₁₄B. A discontinuity in the magnetization occurs when the magnetic field is applied along the [100] direction in the hard basal plane below 220 K while there is a regular approach to saturation magnetization along the [110] direction. This discontinuity has been interpreted as a first‐order magnetization process. High‐order terms in the free energy are required to account for the spin reorientation transition from easy axis to easy cone and first‐order magnetization process. The temperature dependence of the uniaxial and planar anisotropy energy constants has been determined.