Recording, noise, and servo characteristics of patterned thin film media

In this paper, we present a combined experimental and micromagnetic simulation study of the recording, noise and position error signal characteristics in patterned thin film media. The medium is patterned with a focused ion beam etching technique on typical present thin film disks. It is found the transition noise is completely absent in the patterned thin film media. Comparing with continuous thin film media, the medium noise is reduced to the level of noise at saturation remnant state and is no longer density-dependent. With the elimination of transition noise, the signal-to-medium-noise ratio will be sufficient at very narrow track widths without further reduction of grain size. A slight increase of intergranular exchange coupling will have little impact on medium noise, but enhance thermal magnetic stability of the medium. Down track orientation of the crystalline easy axes will further improve the recording performances. Position error signal patterns in patterned media can be more versatile and significantly more effective and efficient.