Investigation of slider surfaces after wear using photoemission electron microscopy

The tribe-chemical interactions between the slider and the hard disk surface strongly influence the performance properties of a disk drive. To study these interactions, uncoated and carbon coated sliders were subjected to various wear tests using different disks. After the wear, the test slider surfaces were studied by photoemission electron microscopy (PEEM) using tunable x rays produced by a synchrotron. Using PEEM, one can identify the elemental and chemical state of the surfaces with a high spatial resolution. It was found that wear reduces the thickness of the carbon coating in some local areas of the slider surface. In particular, the coating was removed on elevated areas and in scratches. Scratches were found on the rails of the carbon coated and uncoated sliders after wear that showed the accumulation of a degraded (oxidized) lubricant which was transferred to the slider from the disk. It was also possible to analyze the chemical composition of the debris found on the slider surface. In the present case, the debris had the same chemical composition as the carbon coating of the slider. (C) 1999 American Vacuum Society. [S0734-2101(99)08505-X].