Thermally activated magnetization reversal in the micromagnetic approach

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