Paramagnetic torque in cubic rare-earth compounds.

Abstract

Paramagnetic torque appears in cubic rare-earth intermetallics as an interesting experimental probe for studying the magnetic response to different couplings such as bilinear exchange, crystalline electric field, and quadrupolar interactions. Starting from the high-order magnetic susceptibility tensor for 432, 4\ifmmode\bar\else\textasciimacron\fi{}3m, m3m high-symmetry classes, its expression is given within the mean-field approximation and allows one to determine the anisotropy of the initial curvature of the isothermal magnetization in the presence of an applied magnetic field. It is shown that at the magnetic transition, the twofold axis is never the easy magnetization direction. Torque measurements in the paramagnetic phase of CsCl-type structure compounds, TmZn and TmCd, are then presented. They are in full agreement with the third-order magnetic susceptibility previously studied and allow a more precise determination of the quadrupolar interactions in these systems.