High Anisotropy Y-Co Films on Thin Cu Underlayer

The role of Cu underlayer for preparing CaCu₅-type high magnetic anisotropy YCo₅ phase was studied. We prepared the Cu/YCo structure with a DC magnetron sputtering deposition system under elevated substrate temperatures. We successfully produced magnetic films which contains a high-Ku Y(Co, Cu)₅ phase using a 7.5-nm-thick Cu underlayer, and under the growth temperature of 470 degC and above. The film has the perpendicular c-axis orientation with spread of 3deg. At 470 degC growth temperature, the film consists of a crystalline Cu-rich Y(Co, Cu)₅ phase and an amorphous Co-rich Y(Co, Cu)₅ phase. A rather thin Cu underlayer thickness of 7.5 nm was sufficient for obtaining a good perpendicular c-axis orientation, and the high-Ku phase production