The Relaxation Effects in the Preisach - Néel Model of Patterned Media

In this paper, we present the calculation of thermal magnetic viscosity based on numerical simulations of relaxation isotherms curves for a Stoner–Wohlfarth ensemble. The Stoner–Wohlfarth particles is described by two equilibrium states and thermal activation is done by overcoming the energy barrier. For simulations we have used a new Preisach type model for Patterned Media, which takes into account the effects of time and temperature. The magnetization of the system is treated using the Preisach Model for Patterned Media with bimodal interactions field distributions. We have simulated relaxation curves starting from different points on the negative region of the descending branch of the major hysteresis loop and from the obtained data we evaluated the thermal fluctuation field. The results obtained for the linear energy barrier were compared with the non-linear energy barrier.