Magnetic properties of Co-Cr films on Co-Cr under-layer with various composition

Double layer Co-Cr films with under-layer Co-Cr of various composition and single layer Co-Cr films were continuously prepared by DC magnetron sputtering on PET film, using Co-Cr alloy targets. The dependences of , Hk and Δθ50of double layer Co-Cr films on Cr concentration of under-layer film were measured. The anisotropy field Hk of double layer Co-Cr film is higher or lower than that of single layer Co-Cr film in accordance with whether the Cr concentration of under-layer Co-Cr film is higher or lower than that of over-layer Co-Cr film. On the other hand, the dependence of of double layer Co-Cr film on Cr concentration of under-layer Co-Cr film is contrary to that of Hk. The crystal orientation of double layer film depends on that of under-layer film. It seems that double layer film would grow epitaxially on under-layer film.