Dependence of the anhysteretic magnetization on the demagnetization factor

A method is presented to measure the dependence of the anhysteretic magneti zation curve (the anhysteretic magnetization as a function of the internal field after degaussing) on the demagnetization factor N without physically varying N. The relation between the Preisach distribution and the N depende nce of the anhysteretic magnetization curve is discussed in a way that is v ery close to the work of Bertotti. Classes of (moving) Preisach models are identified for which the anhysteretic magnetization curve is independent of the demagnetization factor. It is proven that the anhysteretic magnetizati on increases with N at fixed internal held, if the Preisach distribution de creases monotonically with increasing H-cent, the internal field value of a Preisach domain. It is shown that the Moving Preisach model may lead to a negative anhysteretic permeability. (C) 2000 Elsevier Science B.V. All righ ts reserved.