Magnetic recording on patterned media prepared by ion beam irradiation

We perform fully integrated micromagnetic simulations of patterned recording media to optimize the recording process.Fully integrated simulation contains the induction coil in the write head, the yoke, the pole tips, shields, return pole, recording media and magnetic soft under layer (SUL). The magnetization behavior of the media is calculated by taking into account the interactions and back interactions between head, media and SUL.From our simulation results, we can see recording mechanism of exchange coupled patterned media. At first, the soft magnet region is reversed by the write field from the head. Then, the domain wall that is formed in the soft grains propagates into the hard phase. Therefore in the case of weaker intergrain exchange coupling, a higher head field is required to write bits.In order to test the stability of one bit of the patterned media, the hysteresis loop of one bit was calculated. The coercive field decreases with increasing intergrain exchange.This is closely related to the problem of adjacent track erasure for the limit of high intergain.