DETERMINATION OF LUBRICANT FILM THICKNESS ON A PARTICULATE DISK SURFACE BY ATOMIC FORCE MICROSCOPY

Here, we demonstrate the ability of the atomic force microscope (AFM) to measure the lubricant film thickness on the surface of particulate disks. For an unused disk, we find 50-70 Å of lubricant thickness. After the disk has been in use for several years, the lubricant thickness decreases to 35-55 Å. In both cases, the lubricant is uniformly distributed on the disk surface, although somewhat more uniformly on the used disk. For all types of disks studied, most of the lubricant resides below the disk surface, presumably in the media porosity, with only a molecularly thin film of lubricant on the surface. © 1990 IEEE