Dependence of initial drive field on switching rate in 50-50 Ni-Fe tape cores

The drive field required for rapid constant-rate magnetization reversal in 50-50 Ni-Fe tapes rises approximately linearly in accord with Ganz saturation wave theory only after an initial nearly level step. Analysis of the initial stages of magnetization reversal in terms of the motion of domain walls severely bowed against the wall surface tension by the inhomogeneous eddy-current field leads to the square root dependence of the step field on switching rate reported by Winter et al. [1].