Changes in Magnetization of Single-Crystal Dysprosium, Erbium, and Holmium in High Magnetic Fields

Abstract

Measurements are reported on the behavior of magnetization with field of single-crystal dysprosium, erbium, and holmium in pulsed magnetic fields up to 165 kOe. These elements go progressively on decreasing temperature from a paramagnetic to antiferromagnetic to ferromagnetic state. Sufficiently high external fields applied along spin axes in single-crystal samples can cause spin realignment by overcoming the internal exchange and anisotropy fields. The strengths of the internal fields can be determined in this manner. Measurements with an external field H applied in the basal plane of Dy and of Ho, and with H parallel to the c axis in Er, confirm previous static field measurements of Hc for the AF/F transition. No change in spin alignment is seen in Dy with H parallel to c up to 165 kOe. In Ho below 80°K fields near 100 kOe produce strong changes in magnetization with H parallel to the c axis. Below 20°K fields up to 17 kOe in the basal plane in Er produce a sharp change in magnetization indicative of spin realignment. The magnetization of Er with H parallel to a is measured at 4.2°K in static fields up to 56 kOe. The magnetization increases sharply between 15 and 20 kOe, reaching 50 emu/g at 20 kOe. Little change is found above 40 kOe where M is 120 emu/g. These results are discussed with regard to the internal fields in Dy, Ho, and Er.