Media Noise Characteristics of CoCrTa/FeSiAl Perpendicular Magnetic Recording Media

Media noise characteristics of CoCrTa/FeSiAl perpendicular magnetic recording media were investigated to clarify the effects of underlayer characteristics such as crystalline orientation, surface roughness on the medium noise of double-layer media. A strong correlation was found between maintaining a smooth underlayer surface and attaining a low level of medium noise. Insertion of a Cr layer between the glass substrate and the FeSiAl underlayer and sputtering the underlayer at low Ar-gas pressure are effective in maintaining its surface smoothness. These measures reduce medium noise.