Coupling and crystallographic effects in thin film cobalt alloy recording media

Intergranular interactions and time dependence effects have been studied in two classes of Go-alloy ternary and quaternary thin films. The role of integranular 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 Delta I(H) technique that ex-change 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.