Ar-sputtered Pt/Co multilayers with large anisotropy energy and coercivity

We have discovered a process for Ar-sputtering Pt/Co multilayers, a candidate for high density magneto-optical recording medium, so that they have large anisotropy energy (K_eff ~1.2×10⁷ erg/cm³-Co) and large coercivity (H_c ~3.5 kOe) simultaneously. To achieve these improved properties the multilayers were sputtered on granular Pt underlayers, made by etching thin Pt layers, initially 20-40 Å thick. Plan-view transmission electron microscopy revealed that the microstructures of Pt/Co multilayers, grown on etched-Pt underlayers, was also granular with excellent (111)-fcc texture. Both K_eff and H_c were optimized, when the (111)-fcc texture was a maximum