On magnetic first-order transitions in erbium

Abstract

The magnetic transitions in a single crystal of erbium have been investigated with a high-resolution scanning microcalorimeter. The transition between the ferro- and antiferromagnetic states takes place at 19.2 K (Tc) and is of first order with a latent heat of 18.5+or-1.0 J mol-1. In the antiferromagnetic state between Tc and 51 K four small energy peaks were observed which are ascribed to commensurate transitions. These transitions exhibit hysteresis effects and are of first order. At 53.4 K a relatively localised energy peak of 1.3+or-0.3 J mol-1 was found which probably arises from the ordering of the basal-plane moments. Also this transition was found to have a temperature hysteresis and is of first-order type. The antiferro-paramagnetic transition occurs at 85.6 K in this sample and its second-order nature is confirmed.