A 2-DIMENSIONAL VECTOR MODEL OF FERROMAGNETIC HYSTERESIS

A new two-dimensional vector model of ferromagnetic hysteresis, which we have designated the UB model, is presented in this paper. Two types of entities constitute the model: uniaxial particles, having an energy per unit volume according to the Stoner-Wohlfarth (SW) theory, and biaxial particles that differ from the former in the magnetocrystalline energy term. The equilibrium distribution of magnetisation corresponds to an energy minimum for all particles that constitute the model. A description of the model identification is also reported. The process, although essentially different, bears some resemblance to the one used to identify the simplified Preisach model [1] (all the Preisach surface contents concentrated along the two axes of the plane) and requires knowledge of the major hysteresis loops of the specimen under study along the x and y directions. The relationship between experimental values and model parameters is obtained taking into consideration the link that is established between an SW-type particle and Preisach entities. The paper ends with examples where UB model performances are displayed.