Signal-to-noise ratio and thermal stability issues in extending synthetic ferrimagnetic media technology over 100 Gb/in/sup 2/

Signal-to-noise ratio (SNR) and thermal stability issues are addressed to evaluate synthetic ferrimagnetic media (SFM) for achieving areal densities >100 Gb/in/sup 2/. Thermally stable SFM is obtained at M/sub r/(delta) values as low as 0.15 memu/cm/sup 2/, utilizing a higher magnetic anisotropy for the stabilization magnetic layer. The SNR relations for SFM are decided by the effective M/sub r/(delta) and coercivity, similar to conventional media. The recording characteristics of a low M/sub r/(delta) medium was compared with a higher M/sub r/(delta) medium used for the 106-Gb/in/sup 2/ demonstration. Lower medium noise and higher signal resolution of the lower M/sub r/(delta) medium indicate an areal density extension to beyond ~150 Gb/in/sup 2/.