Magnetic anisotropy in RCo3 (R = Lu and Y) single crystals

Abstract We report on magnetization measurements of LuCo3 and YCo3 single crystals. These compounds show an instability of the 3d-subsystem, whereby the Co atoms go from a low-spin to a high-spin state in applied magnetic field. In the low-spin state, we find a pronounced anisotropy of the saturation magnetization for LuCo3 and YCo3, which can potentially lead to a large error in the determination of the anisotropy constant, K2, whereas the constant, K1, is much less affected. We also show that Belov-Arrott plots yield different values of the Curie temperature than obtained by magnetization curves along different crystallographic directions.