Influence of Cr addition on the magnetic softness of nanocrystalline FeCuNbSiB alloys

The compositional dependence of the effective anisotropy of as-quenched and thermally treated, Cr substituted FeCuNbSiB melt spun samples, is examined through the results corresponding to the measurement of the transverse biased initial susceptibility. The analysis of these experimental data allowed us to evidence the occurrence of magnetization ripple and to evaluate the evolution with the thermal treatments of the so-called dispersion field and of the dimensions of the coupled magnetization regions underlying the measured values of the effective anisotropy. It is concluded that magnetostatic interactions play (in addition to exchange interactions) a major role on the formation of these coupled regions.