Surface texture assessment in the tangential direction of a rigid magnetic disk to reduce the friction force between head and disk surface

The disk surface texture was assessed in both the radial and tangential directions to estimate the size and number statistics of real contact spots at the head-disk interface and the friction force between head and disk surface. It was demonstrated that textured disks having similar characteristics in the radial direction show different profile features in the tangential direction. The relatively large values in wave peak undulation and its tangential spacing in the tangential direction reduced the frictional force in CSS tests. The friction force increases with apparent radius of curvature of the significant wave peaks determined by rolling a virtual circle over the macroscopic profile in the tangential direction