EFFICIENT NUMERICAL-MODEL OF MAGNETIC SWITCHING OF FINE PARTICLES WITH UNIAXIAL ANISOTROPY

The important role played by the magnetic reversal mechanisms of particles constituting a magnetic medium in determining its bulk magnetization, is increasingly being recognized. The classical Stoner-Wohlfarth (SW) coherent rotation model, or modifications of it, have been extensively used to model media particles, although it has limited validity. Recent insights provided by detailed numerical micromagnetic investigations of fine particles, suggests the need for a reappraisal of the above approach. This paper describes a general numerical switching model for a single particle with uniaxial anisotropy. The model is computationally efficient enough to be included in a bulk hysteresis model. The input to the model is a limited amount of information about the particle switching obtained from a detailed micromagnetic analysis of it.