Optimization of low-noise media for 100-Mb/in.2 recording with a magnetoresistive head

Abstract

Single-layer and multilayer longitudinal media were evaluated for 100-Mb/in.2 recording at a 6-μin. flying height with a magnetoresistive head. It was found that the multilayer media produced transition jitter values that were at least 23% below comparable single-layer results. Timing margins, estimated from the measured jitter and asymmetry data, indicate that single-layer media may prove marginal for this application. Multilayer timing margins were projected to be 40%. Signal-to-noise ratio, resolution, and overwrite comparisons are also made for both types of media. The improvements demonstrated with the multilayer media are attributed to the reduced media noise associated with this type of structure. Increased Cr spacer layer thickness in the multilayer media was found to increase jitter and reduce the D70 density response.