Problems of loss separation for crystalline and consolidated amorphous soft magnetic materials

Losses were measured as a function of magnetization frequency f/sub d/ for two advanced soft magnetic alloys: laser-scribed 0.23-mm HI-B steel ZDKH (designated HB) and consolidated amorphous Powercore (designated PC). Although domain observations on HB yielded distinct domain refinements due to the laser treatment, anomalous losses W/sub a/ still proved to be higher than the classical ones. A further refinement resulted from increasing f/sub d/. Thus, anomalous eddy current losses were reduced while hysteresis losses were increased. As a consequence, it is suggested to separate W/sub a/ into an eddy current component and a hysteresis component, which arises in addition to the classical hysteresis loss. With increasing f/sub d/, especially wide domains were refined. Results of loss measurements performed at high f after demagnetization with low f/sub d/ indicated similar bar-type domain structures in HB and PC, the domain widths of the latter exceeding those of HB, however, by one order of magnitude. A Kerr-effect scanning technique confirmed the existence of an inner bar-type domain structure with domain widths of some millimeters.>