HIGH SNR PERPENDICULAR RECORDING MEDIA

We investigated the effect of a Ti interlayer in perpendicular double- layer disks to give a typical columnar structure and a good crystal or ientation. Coercivity in thinner Co-Cr with Ti is larger than that wit hout Ti. However, we found the Ti layer was not good for high density recording because of its spacing loss. The effects of Ta in a Co-Cr la yer on coercivity are also studied particularly in thin film. The effe ct of Ta is similar to that of a Ti interlayer in coercivity but very superior in recording characteristics. We also measured signal-to-nois e ratio at very high density and got 16 dB of SNR at a density of 2 Gb it/in2 using the Co-Cr-Ta film.