Signal-to-noise ratio and thermal stability issues in extending synthetic ferrimagnetic media technology over 100 Gb/in2

Signal-to-noise ratio (SNR) and thermal stability issues are addressed to evaluate synthetic ferrimagnetic media (SFM) for achieving areal densities >100 Gb/in². Thermally stable SFM is obtained at M_rδ values as low as 0.15 memu/cm², utilizing a higher magnetic anisotropy for the stabilization magnetic layer. The SNR relations for SFM are decided by the effective M_rδ and coercivity, similar to conventional media. The recording characteristics of a low M_rδ medium was compared with a higher M_rδ medium used for the 106-Gb/in² demonstration. Lower medium noise and higher signal resolution of the lower M_rδ medium indicate an areal density extension to beyond ∼150 Gb/in².