Lattice matching effect of Co-(Cr,Ru) alloy underlayer on magnetic properties of Co-Cr-Pt longitudinal recording media

Magnetic properties are investigated for Co-Cr-Pt thin films deposited on nonmagnetic h.c.p.-Co(Cr,Ru) underlayers with different h.c.p. lattice constants. Higher coercivity, higher coercive squareness, and lower fluctuation field are observed when the h.c.p. lattice constant is close to that of the Co-Cr-Pt recording layer. Temperature dependence of magnetic properties indicates that employment of nonmagnetic Co-Cr-Ru layer is effective to increase the coercivity and to enhance the thermal stability of recording layer.