Write-field interference in the recording process on Co-Cr media: an experimental study

The frequency response of Co-Cr media, recorded with a ring head, shows a series of additional minima. Investigation with a write head with a large gap (3 μm) revealed that the effect can be modeled as a double transition recorded by the fields at the leading and trailing edges of the head. It was found that the magnitude of the second transition decreases when the recording current is increased above the optimum value. The thickness of the Co-Cr layer has no significant influence on the magnitude of the minima. However, a decrease of the effective perpendicular anisotropy results in a smaller magnitude of the minima. These observations are confirmed by VSM simulations