Micromagnetism in Amorphous Alloys

Brown's micromagnetic equations are derived for the case of dipolar and "magnetocrystalline" fluctuations in amorphous ferromagnetic alloys. The influence of these fluctuations and the effects of internal stresses of so-called quasi-dislocation dipoles on the law of approach to ferromagnetic saturation is discussed in detail. It is shown that intrinsic fluctuations of magnetic properties lead to a
1/\sqrt{H}
-term in the high-field range whereas internal stresses give rise to
1/H
- and
1/H^{2}
-power laws. A quantitative analysis of experimental results indicates that internal stresses dominate the effects of intrinsic fluctuations considerably.