Temperature induced shift of the demagnetization curveof anisotropic ferrite magnets

Abstract

Higher specifications and more narrow tolerances for electrical motor appliances give sense to a renewed interest in the temperature dependence of the demagnetization curve of anisotropic ferrite magnets. Based on physical backgrounds, a first approximation modelling is given for the temperature dependence of a working point, using the room temperature curve and some material and system characteristics. A procedure is derived to give the induced shift of the whole curve at any temperature (−100 to 300 °C). An important characteristic for the application is the field Hki, where irreversible flux losses start. Hence, the critical temperature decrease, at which Hki is reached in the system, is derived.