Magnetic hysteresis model for magnetic recording including spatial fluctuations of interaction fields

For materials with a particulate structure, Neel was the first to point out the importance of statistical fluctuations of the magnetic interaction fields. He has shown how they influence the material behavior and how reptation can be generated. These aspects are not taken into account by some classical hysteresis models, e.g., the Preisach model. A recent paper by Della Torre and Kadar [IEEE Trans. Magn. MAG‐23, 2820 (1987)] improved the Preisach model in order to consider the influence of fluctuations. Our paper presents an hysteresis model, based on the superposition of the elementary characteristics of single bistable particles. The interaction field is assumed to have a Gaussian statistic distribution, with a mean value and a standard deviation depending on the macroscopic magnetization. The spatial fluctuations of the field acting on the bistable particles are seen to enhance the mean‐field components. Being that the fluctuations are stronger when the material is macroscopically demagnetized, it is e...