High Density Perpendicular Magnetic Recording by Ring Head and Vacuum-Deposited Co-Cr Single-Layer Media

Investigations using narrow gap ferrite video heads and vacuum-deposited Co-Cr single-layer media are reported. The characteristics of ring head and single-layer film combinations, in particular the perpendicular recording capability, were discussed from the point of view of the di-pulse ratio (DPR) of isolated transitions. It was found that although ring head perpendicular recording capability declines as the gap length is reduced, and the isolated pulse´s DPR itself gets smaller, reduction in recording demagnetization due to reduction in gap length actually improved the recording density.