Chemistry of magnetic recording disk surfaces with intermittent asperity contacts

Since many of the newer disk drive products incorporate load/unload to avoid starting and stopping on the disk surface, a new low-velocity accelerated life test was developed to simulate the tribology at ultra-low flying height with asperity contacts. Surface chemical analysis of the tested regions detects lubricant removal by desorption, and fragments with a carboxylic acid end group and their organic amine salts. An increase in the water adsorption on the tested regions is attributed to the hydrophilic carboxylic acid groups.