Effects of wall pinning on bias susceptibility measurements

A technique was devised to obtain a quantitative measure of some of the internal magnetostatic fields in a thin Ni-Fe film which are present when the film is broken up into strip domains whose average angular orientations are parallel to the average easy axis. The process involved the experimental-numerical evaluation of the average angle which the magnetization makes with the easy direction as a function of a transverse dc bias field. These angles were found for all bias field values from zero to saturation. It was found that one of the internal fields, a demagnetizing type field brought about by wall and ripple boundary pinning, was very instrumental in effecting an explanation of the experimentally observed bias susceptibility measurements.