XPS determination of lubricant film thickness on thin film magnetic recording disk

Experimental electron mean free paths were utilized to determine the thickness of the lubricant film on thin-film magnetic recording media. Electron mean free paths were obtained by experiments which provided multipoint data on the C-F peak height ratio vs. the lubricant thickness. The thickness of the lubricant film on the thin-film magnetic recording media was calculated from the diameter of the dripped lubricants solution measured by optical microscope, the lubricant density, and the concentration of the lubricant solution. The C-F peak height ratio as measured by XPS was then plotted against the thickness. The electron mean free path was determined from the approximate slope, which corresponds to an exponent. This experimental electron mean free path was compared with previously reported values. It is thought that the method used is the best available for calculating the electron mean free path, from which the lubricant film thickness can be determined with a more specific value than using the published mean free path to compute the lubricant thickness.