COLL 110 |
| C. Mathew Mate1, Patrick C. Arnett1, Qing Dai1, Bernhard E. Knigge1, Francis C. Lee1, Oscar J. Ruiz2, and Robert J. Waltman2. (1) IBM Almaden Research Center, 650 Harry Rd., C3, San Jose, CA 95120, (2) IBM Storage Technology Division, 5600 Cottle Rd., San Jose, 95193 |
| Here, we report a new experimental technique for measuring the shear properties of molecularly thin lubricant films (thickness < 2 nm) between two nearly atomically smooth surfaces (rms roughness < 1 nm) at high speeds (> 10 m/s). The experimental geometry consists of a slider on a rotating disk, similar to that found inside of disk drives, but with the slider designed to run with a small pad in continuous contact with the disk. With this technique, friction forces and relative spacing changes are monitored as a function of contact conditions and lubricant type. We find that the transition from stick-slip motion to smooth sliding is promoted by increasing surface roughness, decreasing lubricant mobility, decreasing contact pad size, and decreasing sliding speed. Various molecular level models will be discussed to explain the observed effects. |
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Molecular Tribology
Division of Colloid and Surface Chemistry |