Magnetic and recording characteristics of very thin metal-film media

The recording performance of very thin sputtered Co-alloy longitudinal film media has been examined. Measurements made using magnetic layers as thin as 50 AA show that the thinner films exhibit improved signal-to-noise characteristics. Similar trends have been observed in both CoNiCr and CoPtCr alloys on Cr and CrV underlayers. Improvement in signal-to-noise ratio is accompanied by a reduction in coercivity squareness as the film thickness is reduced. Large variations of coercivity with film thickness are also observed in the range 50-300 AA. It is suggested that changes in grain size and grain boundary separation during the early stages of film growth play a role in these effects.<
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