INVESTIGTIONS OF COMPOSITIONAL SEPARATION OF CO-CR-TA CR THIN-FILM RECORDING MEDIA

The compositional distribution in Co-Cr-Ta thin films is investigated as a function of Cr underlayer texture and substrate temperature (T(s)) using spin-echo nuclear magnetic resonance and preferential chemical etching. Both the extent and pattern of compositional separation (CS) show no variation with Cr underlayer texture. Elevated T(s) is observed to promote both CS and grain boundary Cr enrichment. The magnetic anisotropy fields of Co-enriched components in the films are observed to increase with T(s), explaining the T(s), dependence of H(c). Ta addition is observed to control the distribution of Co and Cr, leading to a unique compositional microstructure which may enhance the magnetic and recording properties.