Longitudinal magnetic media designs for 60-200-Gb/in2 recording

Areal density growth in longitudinal magnetic recording requires physical scaling of component features and properties that cannot continue indefinitely. The authors discuss in this paper the limitations and extendibility of longitudinal recording media focusing on its microstructural features and historical rate of change. Based on these trends, they estimate that an areal density of 200 Gb/in² is achievable. In order to make such media thermally stable, synthetic antiferromagnetic structures will likely be used. The crystallographic grain size will be between 5 and 6 nm and the coercivity of the media will likely not exceed 5000 Oe. Additionally, a significant decrease from current values in the width of the grain size distribution will need to occur to satisfy SNR requirements in the drive.