Mechanisms of the Magnetic Properties Improvement of Amorphous Soft Magnetic Fe- and Co-based Alloys as a Result of the in-air Heat Treatment

Physical causes of the formation of magnetic characteristics amorphous soft magnetic alloys under heat treatment in air have been studied. It has been established that the physical causes of the formation of the magnetic characteristics of the cobalt-based alloys are the same as those for iron-based alloys. Change in the magnetic characteristics after annealing results from the relaxation of the quenching induced internal stresses, as well as from the effect of the stresses induced by the hydrogen and oxygen atoms embedded into the ribbon surface in the course of its interaction with water vapor in air and by the formation of the amorphous-crystalline surface layer. The study of the magnetization distribution and the magnetic characteristics of the Co-Fe-Ni-Cr-Si-B amorphous soft magnetic alloy have shown the possibility of using the vapor treatment of the amorphous soft magnetic alloy ribbon surface to determine the sign of its magnetostriction. The magnetostriction sign dependence on the structural state of the ribbon is found on the basis of the obtained results.