A two-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: u niaxial particles, having an energy per unit volume according to the Stoner-Wohlfarth (SW) theory, and b iaxial 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.