Thermal switching probability distribution of L10 FePt for heat assisted magnetic recording

Transition jitter is one of the most important parameters for evaluating the potential areal density of Heat Assisted Magnetic Recording. However, obtaining this either experimentally or through micro-magnetic simulation is time consuming. Here, we show that the more easily calculated thermal switching probability distribution (SPD) can serve as a substitute. In particular, we provide an equation relating the standard deviation of write temperature to the jitter. The equation is verified for three critical noise sources: T_c variance, H_K variance, and grain size distribution. In addition, the SPD subject to cooling at various cross-track positions is investigated. A method to determine the magnetic grain size is proposed.