Magnetic and magnetoelastic anomalies of an Er2Co17single crystal in high magnetic fields

Abstract

A high-field study of magnetization (up to 68 T) and magnetoelastic properties (up to 60 T) of Er${}_{2}$Co${}_{17}$ is reported. The most significant effect, a first-order transition from the collinear ferrimagnetic to a canted state, is observed at about 40 T with H \ensuremath{\parallel} [001]. The transition is accompanied by a prominent magnetization jump as well as by step-wise anomalies of the magnetoelastic properties. Thus, the volume of the crystal reduces by about 4 per mil, while the speed of transverse sound in the [001] direction increases by as much as 5 per mil. At higher temperatures the anomalies gradually become smaller and less sharp before they finally disappear at \ensuremath{\sim}50 K. The anisotropy constants of the Er sublattice and the molecular field thereon have been determined from the magnetization curves.