Domain wall bowing interpretation of eddy current loss measurements in a (110) [001] Si-Fe monocrystal

Abstract

The measurements of cyclic magnetization loss in a 3% Si-Fe monocrystal with known domain structures reported by Swift et al. (1974) are compared with the predictions of the Pry and Bean model, a skew planar wall model, and a model of domain wall bowing which neglects the dependence of domain wall energy per unit area on the crystallographic orientation of the wall. Detailed agreement is not obtained, but the trend of the bowing model behaviour is encouraging. Consideration of the consequences of the dependence of wall energy on orientation indicates that it should assist the initiation of bowing at lower frequencies and restrain severe bowing at high frequencies. This is expected to lead to a reduction in the losses, especially at low frequencies, and to a general straightening of the loss/frequency characteristic in accord with the trend of the observations. The discrepancy between the measured losses and the Pry and Bean model has previously been attributed to edge effects according to the calculations of Young et al. (1975) It is shown in the present paper, however, that the Pry and Bean model requires negligible correction for edge effects provided the domain walls are well separated on the scale of the sheet thickness.