Thin-film media with compositional gradient for high-density recording

A sputtering technique for mixing two or more magnetic alloys has been developed. This technique produces magnetic compositional-gradient along film thickness. CoNiCr and CoCrTa-magnetic alloys were used for this sputtering scheme. In one case, the low-noise characteristics of the first magnetic layer-CoCrTa with Ms:659 emu/cc is combined with the high Br, remanence magnetization characteristics of the second magnetic layer-CoNiCr with Ms:1110 EMU/CC. The performance of CoNiCr/CoCrTa-gradient media was better than the CoCrTa/CoNiCr-gradient media. Magnetic and recording properties of the gradient thin-film media were compared with the single-layer media of CoNiCr and CoCrTa. The coercivity of gradient media was about 20% higher than their single-layer media. The remanence magnetization of gradient-media is about 25-30% higher than the CoCrTa-single layer media. Also, CoNiCr/CoCrTa-compositional gradient media produce about 40% lower media-noise in comparison to CoNiCr-single layer media