Effect of circumferential texture on the properties of thin film rigid recording disks

The magnetic recording medium of C/CoNiCr/Cr was DC magnetron sputtered onto rigid disk substrates of various circumferential textures. The texture was characterized by mechanical and optical surface profilometry. Texture increased circumferential coercivity and squareness. Recording signal and signal-to-noise ratio improved while overwrite worsened. Structural inhomogeneities in the carbon overcoat along the texture lines increased with texture. Texture improved the head-disk friction characteristics and increased the head lift-off time during start-up. Too coarse a texture led to performance degradation.