Field Dependence of the Magnetic Anisotropy of Gadolinium at 4.2 K Under High Pressures

Abstract

In a previous publication (Franse and Gersdorf, 1980) we reported the anomalous behaviour of the torque, due to magnetic anisotropy, of a gadolinium single crystal in the (c,a) plane at low temperatures. The anomalies were ascribed to a peak in the density of states curve that moves through the Fermi level upon rotating the magnetization vector with respect to the hexagonal axis. By studying the pressure dependence of the magnetic torque at 4.2 K some of the peak parameters could be determined. From preliminary experiments under high pressures at 25 K the width in energy of this peak was estimated and subsequently the spin orbit interaction parameter and the number of electron states contained in the peak (about 5 x 10⁻⁴ electrons/atom). In order to understand this anomaly further we studied the field dependence of the magnetic torque at 4.2 K under high pressures with magnetic field intensities of 1.8 T and 4.8 T.