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 degrees C and above. The film has the perpendicular c-axis orientation with spread of 3 degrees. At 470 degrees C 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 run was sufficient for obtaining a good perpendicular c-axis orientation, and the high-Ku phase production.