Thermal Reversal of Magnetic Grains Under Time Varying Pulse Field

Media thermal magnetization switching under an arbitrary time varying field, pulse shape, and duration is an important issue in many recording applications. This paper shows a scale dilemma in using the time dependent energy barrier approach to describe long time thermal reversal of magnetic grains under a time varying pulse field. A new model approach based on an optimal reversal path is proposed to characterize the thermal reversal behavior of magnetic grains under an arbitrary time varying pulse field. Using this new model approach, the effects of pulse field duration, width, and amplitude on magnetic grain thermal switching behavior are studied.