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 50A show that the thinner films exhibit improved signal-to-noise characteristics compared to thicker media. Similar trends have been observed in both CoNiCr and Copter 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 decreased. Large variations of coercivity with film thickness are also observed in the range 50-300Å. 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. © 1989 IEEE