Magnetization of erbium monocrystals in the basal plane in strong magnetic fields

The magnetization of erbium located in fields approximately 300 kOe is measured in the basal plane along the b axis at temperatures between 4.2 and 64 K. A discontinuity in the magnetization approximately 0.82 μsub(B) per atom is observed in the 4.2-35 K range and a field approximately 270 kOe after which saturation sets in. THe temperature dependences of the critical fields in the temperature range of existence of the discontinuity are derived from measurements of the differential susceptibility. It is shown that the low-temperature anomalies of the magnetization of erbium in the basal plane along the haxagonal c axis may be explained in the anisotropic molecular field approximation