Simulations of ultra-fast precessional switching of AFC thin film storage media

Micromagnetic simulations of the application of perpendicular field pulses to in-plane antiferromagnetically coupled (AFC) thin film disk media have been performed. Starting from a thermally relaxed state, application of a perpendicular field pulse to an in-plane medium results in fast in-plane precessional rotation. Our simulations indicate that 180° magnetization reversal of both AFC layers can be achieved by selecting the correct pulse duration, and that repeated reversal can be achieved with no significant decay of magnetization. Switching times as short as 8 ps are required, suggesting that ultra-high data rates could be achieved. Studies of the effect of pulse shape indicate that reversal and recording will be possible with the non-square pulses that would be expected from practical write heads.