Kinetic and structural aspects of magnetic phenomena in amorphous soft ferromagnets

Abstract

Some recent results concerning domain structure and domain-wall motion in amorphous soft ferromagnets are reviewed. The effect of the value of the saturation magnetostriction is discussed, with particular emphasis on the change in sign of λ_s induced in nearly-zero magnetostriction alloys by large tensile stresses. The ‘fast’ permeability relaxation observed during high-frequency domain-wall motion is explained in terms of a domain-wall instability under extreme velocity conditions. Finally, the unique kinetic features of the slow relaxation (after-effect) of the initial magnetic permeability will be outlined. A specific experiment, conceived to check the assumptions of the model established for this relaxation process, is proposed and discussed in detail.