Effect of orientation ratio on recording performance for longitudinal thin film media

The effects of orientation ratio (OR) on longitudinal thin film media recording performance are studied via micromagnetic modeling. The OR of the media is controlled by the anisotropy axes distribution. Along the preferred anisotropy direction, the coercivity and the remanence increases with decreasing standard deviation of anisotropy distribution σ and gives rise to an OR as high as 90. Highly oriented media show an ultra low transition noise and high effective track width. However, it is observed that highly oriented media exhibits a large track edge bending which increases the track edge noise. Effect of saturation magnetization (M_s) on the recording pattern for highly oriented media (OR=22.5) is investigated. Low magnetization is found to induce even lower transition noise and slightly higher effective track width. Edge percolation is observed when M_s increases up to 800 emu/cm³. However, the noise magnitude at this edge does not change much when M_s, is decreased to 200 emu/cm³