Experimental study of lubricant-slider interactions

A simple method is introduced to contaminate either the slider or the disk with a small amount of lubricant, with the intent of studying the interaction between the slider and the lubricant layer on hard disks at low mechanical fly heights. Lubricant ripples at a frequency of 220-280 kHz, corresponding to the second pitch mode of the sliders used, were observed on the disk with an optical surface analyzer. Using laser Doppler velocimetry. a corresponding fly height modulation of up to 20 nm was measured on the slider body. It is hypothesized that this is due to a sustained stick-slip mechanism involving lubricant bridging.