DEPENDENCE ON THE TEMPERATURE OF MAGNETIC ANISOTROPIES IN FE-BASED ALLOYS OF FINEMET

This paper deals with magnetic anisotropies in Fe-based nanostructured materials. Alloys of Finemet are studied which were obtained from amo rphous ribbons by zero-field annealing and by annealing in longitudina l or transverse magnetic fields. A comparison is made between the anis otropies induced during the production processes and those induced by applying external stresses. The analysis is carried out, at temperatur es in the range 20-300 K, through the behavior of the initial magnetic permeability and the saturation magnetization intensity. The anisotro py constant values show an increase with decreasing temperature that c an be well described by an exponential dependence and are always one o r two orders of magnitude lower than the local magnetocrystalline anis otropy. The results are considered on the basis of the random anisotro py model generalized to two magnetic phase systems.