Rare Earth Metal Single Crystals. I. High-Field Properties of Dy, Er, Ho, Tb, and Gd

Abstract

Magnetic-moment measurements have been made along principal axes of Dy, Er, Ho, Tb, and Gd single crystals at 4.2°K and dc fields to 150 kOe. Dy and Tb showed similar magnetic properties. Saturation along the easy axis was achieved at low fields, while along the hard (c) axis the moment was nearly linear with field and did not approach saturation. Anisotropy was observed in the basal plane at low fields. An irreversible change in Dy and Tb occurred below 150 kOe for fields along the hard axis, such that subsequently saturation could not be achieved along the easy axis. Extrapolation of the low-field (unstrained) data along the hard axis indicated anisotropy energies of about 109 ergs/cm3. In Er significant modifications of the zero-field conical moment state were observed and theoretical saturation was almost achieved along the c axis. Fields applied in basal-plane directions collapsed the conical state and produced fan-moment distributions approaching saturation near 150 kOe.