Noise characteristics of double-layered perpendicular media using Fe-Ta-C underlayer

The noise characteristics of double-layered perpendicular media having an Fe-Ta-C soft-magnetic underlayer were investigated. It was revealed that changes in soft magnetic properties and a consequent increase in media noise occurs when C or Ta are reduced from the standard composition. Two-dimensional spike distributions were observed in a medium using the standard Fe-Ta-C composition, possibly caused by temperature inhomogeneity during the annealing process. It was also concluded that the noise contribution of the spikes was minimal for disks using an Fe-Ta-C SMU.