Coupling and crystallographic effects in thin film cobalt alloy recording media

Intergranular interactions and time dependence effects have been studied in two classes of Co-alloy ternary and quaternary thin films. The role of intergranular coupling was investigated in films with sputter texture as well as in films with bicrystal structure. Both classes of media exhibited low noise. It was found via the /spl Delta/I(B) technique that exchange coupling was predominant in bicrystal films while sputter texture samples were magnetically decoupled. The time dependence studies revealed that both sputter texture and a bicrystal microstructure are effective ways to produce thin films with very low activation volumes suitable for high density recording.