Research on the magnetic spectrum of power-supply ferrite materials

In order to study the relation among the four models for the relaxation magnetic spectra and to provide beneficial information for developing ferrite materials, we performed a series of computational analyses and experimental research on the ferrite power-supply materials. A general expression for typical relaxation magnetic spectra is derived. The characteristic parameters can be determined from the experimental mu-f curve by a computational method. The frequency characteristics of the complex permeability (mu) can be calculated by using the basic magnetic parameters and the characteristic parameters. In the ranges of f = 25-1000 kHz and T = 25-100 degrees C, the frequency characteristics of the power loss (P) have been measured and analysed from some power-supply ferrite materials. (C) 1998 Elsevier Science B.V. All rights reserved.