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

Losses were measured as a function of magnetization frequency f_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_a still proved to be higher than the classical ones. A further refinement resulted from increasing f _d. Thus, anomalous eddy current losses were reduced while hysteresis losses were increased. As a consequence, it is suggested to separate W_a into an eddy current component and a hysteresis component, which arises in addition to the classical hysteresis loss. With increasing f_d, especially wide domains were refined. Results of loss measurements performed at high f after demagnetization with low f _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