&stra&-The conventional viscous-flow mechanism microscopic aspects: adsorption, diffusion and evaporation. assoc~ated with the dip-coating technique for lubricant thickness control becomes ineffective for deposition of u~tra-thin films ( < -2 nm) required for hard magnetic disks. We have demonstrated that at least two important icroscopic mechanisms dominate the control of lubricant thickness in this thickness range. They are Evaporation surface adsorption and diffusion of lubricant molecules at the solid-liquid interface.Furthermore, it was also observed that too fast a pulling-up speed resulted in a more nonuniform lubricant film onto the disk surface. This is due to disturbance of the meniscus profile by viscous drag. The uniformity and/or the microstructure of ~ubr~cant layer deposited onto the disk surface will then affect tribological performance.These micro Processes are interrelated and Play an important role in controlling deposition thickness for ultra-thin films. Not to , z V (Pulling-up speed) X Fig. 1. Schematic of the dip-coating. For a static meniscus, hm = [2y/gp] = 1 mm for the solvent used. 1 -Sin0 ]

In this paper, we show that for ultra thin lubricant films (-2 nm) the solvent used in dip-coating of thin film magnetic disks may have a significant effect on the tribological performance of the disk. Two solvents are used in this study. A large difference in CSS performance at 80% humidity is found between using the two solvents. The solvent effect (evaporation, diffusion & adsorption) is believed to determine how lubricant molecules are deposited onto disk surfaces causing different microstructure or conformation of deposited lubricant films during the coating process. This point is further supported by contact angle measurements which show significant different values of DI water on lubricated disk surfaces between using different solvents for the coating of the disks. SurfaceVapor Tension Pressure (dynedcm) (torr)