Eddy-current-limited growth of ferromagnetic domains on the surface of square-loop alloy tapes

Abstract

The expansion of small, initially hemicylindrical domains on the surface of square-loop alloy tapes has been simulated numerically under conditions of (i) constant drive field H_A; and (ii) constant flux-reversal rate d phi /dt. The calculations treat each element of domain wall as being individually in dynamic equilibrium under the pressure of the applied and local eddy-current magnetic fields and the domain wall surface tension. Variation of the specific wall energy per unit area gamma with wall orientation is ignored, and the 'coercive field' H_c is also ignored. By expressing the equations of motion in reduced units, it has been possible to condense all constant H_A growth sequences onto a single sequence and similarly all constant d phi /dt sequences onto another.