ROTATIONAL VECTOR MAGNETIZATION MEASUREMENTS ON NI74MN24PT2 ALLOY

Rotational vector magnetization measurements were carried out on thin disk-like samples of Ni74Mn24Pt2 at T = 5, 12 and 25 K, respectively. The samples were first cooled in a high field to low temperatures and then longitudinal (M(L)) and transverse (M(T)) components of magnetization as a function of the sample rotational angle (THETA) were measured simultaneously in various fields. We have found that a multi-domain structure still persists in a field-cooled state. During sample rotations, each domain restabilizes the balancing opposite torques exerted on it by the external field H and anisotropy field (H(A)), accompanying anisotropy field rotations relative to H, elastically at low temperatures, but dissipatively at higher temperatures. The experimental results were analyzed with a simple torque balance equation assuming that the anisotropy of the sample has only a purely directional component.