Model of thermal erasure in neighboring tracks during thermomagnetic writing

Abstract

A method is presented for the calculation of the thermal erasure of the recorded information in neighboring tracks and implemented for heat-assisted magnetic recording on FePt granular thin films with high perpendicular anisotropy. The thermal erasure in neighboring tracks decays exponentially with distance from the recording head. It is strongly dependent on the heating, grain size, and anisotropy but the write field has a relatively small effect. The track width is dependent primarily on the temperature profile of the laser beam. Secondary effects arising from the write field, anisotropy, intergranular magnetostatic, and exchange coupling are also considered. A more square shaped temperature profile of the laser beam results in substantial improvement in recording properties; enhancement of read signal and sharpness of the magnetic transition and reduction of transition jitter and lubricant loss.