Micromagnetic studies of microstructural dependence of track edge recording on signal and nonlinearities in longitudinal thin film media

Square wave recording in polycrystalline longitudinal thin films is studied by using micromagnetic simulation. Track edge recording is examined for various media with different microstructual properties. Signals and medium nonlinearities are studied by including the track edge recording. From the simulated magnetization patterns, it is found that media with higher intergranular exchange coupling has larger track edge area. The introduction of random anisotropy field magnitude reduces the track edge area. Media with higher intergranular exchange coupling will also have transition percolation occur at a lower recording density. At high recording densities partial erasure starts at the track edges, which yields a reduced effective track width. Magnetic poles at the track edges cause broadening of the playback signals, resulting in a larger PW50 with increased playback track width.