Anhysteretic magnetization and demagnetization factor in Preisach models

The anhysteretic magnetization M/sub an/ depends on the internal field after degaussing H/sub an/ and, possibly, on the demagnetization factor N. Neel's theory of the N dependence is criticized. Classes of Preisach models are identified for which M/sub an/ (H/sub an/) does not depend on N. A numerical method is presented to determine M/sub an/ (H/sub an/, N) from a Preisach model. The zero-field anhysteretic permeability is expressed in terms of the Preisach distribution up to first order in N-k, where k is the parameter of the moving Preisach model.