THERMALLY ACTIVATED MAGNETIZATION REVERSAL IN THE MICROMAGNETIC APPROACH

A theoretical formalism for the treatment of thermally activated magne tization reversal in systems exhibiting incoherent reversal is reviewe d. Thermal effects are first introduced into the micromagnetic formali sm using the Langevin formalism, an approach that has been shown to be effective for studies of thermal activation over small energy barrier s. A different approach based on the ridge optimization method is then used to study the relaxation over large energy barriers. The theory i s discussed in relation to recent pulsed field measurements on particu late recording media. Potential applications such as comparison with a ctivation volume measurements are also discussed.