Micromagnetic simulation of thermal effect in longitudinal thin film disk media

Micromagnetic simulation is utilized to study thermal effects in longitudinal thin film media. A Monte Carlo method is adopted to compute the thermally assisted switching process in a large time scale (from seconds to years). Throughout the study, the ratio of film thickness to grain size is fixed to be 1.67 as grain size varies between 8 and 15 nm. The effective media bulk coercivity is simulated by assuming an applied field duration of 1 s. The thermal decay of both the bulk remanent magnetization and recorded transitions is studied. The thermal effects are compared for media with different intergranular exchange couplings. Media with larger exchange coupling is less susceptible to thermal effect.