Magnetic anisotropy and spin reorientation transitions in a Er2Fe14Si3 single crystal

Abstract Er 2 Fe 14 Si 3 is a ferrimagnet ( T C =474 K, M s =9.6 μ B /f.u. at 2 K). In the ground state Er 2 Fe 14 Si 3 is characterized by a surprisingly low magnetic anisotropy of a “cone of easy axes” type with angle 30° between the magnetic moment and the c -axis. With increasing temperature the anisotropy enhances, the cone closes gradually and transforms by a second-order transition to the easy c -axis at 50 K. Then, at 116 K the “axis to plane” spin reorientation occurs as a first-order phase transition. This transition is accompanied by a large anomaly in the specific heat very sensitive to applied magnetic field.