Effect of disk roughness on slider dynamics

The effect of roughness on the static and dynamic behavior of a taper flat slider on particulate disks of varying roughness and a much smoother thin-film disk has been measured, using a capacitance technique. The results are compared to the behavior modeled for a perfectly smooth disk. The data on the thin-film disk agree very well with the modeling results, but significant differences are observed for the rougher particulate disks. The trailing-edge resting height at zero velocity is higher on rougher disks. At low velocities, the frequency of the normal air bearing mode on the particulate disks is significantly higher than on the thin-film disk. At higher disk velocities, the air bearing mode on the particulate disks is at a lower frequency than on the thin-film disk. This implies that the disk roughness makes the slider fly at an effectively higher flying height at these disk velocities. At low disk velocities the increase in the frequency of the air bearing mode could be due to disk asperity contacts.>