Processes of structural relaxation in the amorphous alloy Co69Fe3.7Cr3.8Si12.5B11 with a near-zero magnetostriction and their effect on the magnetic properties and the characteristics of magnetic noise caused by Barkhausen jumps

摘要

The evolution of hysteretic magnetic properties and the characteristics of magnetic noise caused by Barkhausen jumps have been studied in different ranges of annealing temperature where different processes of structural relaxation develop. It has been shown that the amorphous cobalt-based alloy under study is characterized by a high (in comparison with the iron-based alloys) spatial homogeneity of magnetic noise. The stabilization of domain walls was caused by directional ordering (at annealing temperatures T (a) < T (C)) and the processes of clustering (at T (a) > T (C)) fixed by the method of small-angle X-ray scattering not only affect the level of hysteretic magnetic properties, but also determine the magnetic-noise characteristics of the alloy. A comparison of the dynamics of magnetic-noise behavior with changes in the saturation magnetostriction lambda(s) made it possible to conclude that the magnetic-noise characteristics depend not only on the directional, but also on the isotropic short-range ordering. The ranges of annealing temperature that ensure acceptable values of hysteretic magnetic properties and, simultaneously, a low level of magnetic noise have been established. This situation takes place at a certain optimum concentration of clusters arising in the alloy studied.