Effects of Deposition Rate on Microstructure of CoCrPt-SiO Granular Longitudinal Media for Tape Applications

The microstructure of sputtered CoCrPt-SiO₂ media for tape applications was investigated under different deposition rates. Plan-view and high-resolution cross-sectional TEMs were used to observe the media growth morphology and oxide phase separation behavior. Additionally, time-dependent magnetic property measurements were used for switching volume determination. Although plan-view TEM images suggested well-isolated, small grains, cross-sectional TEM images and switching volume measurements revealed magnetic interconnection between the apparent "grains" visible in the plan-view images. When the deposition rate was reduced from 0.28 to 0.05 nm/s, TEM images showed larger features in plan-view, which is consistent with greater time for atomic motion on the surface before burial. It was also observed in cross-sectional TEM images that columnar growth at the higher rate changed to spheres of metal in an SiO₂ matrix at low deposition rate