&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)

Studies of the effects of substrate temperature T, on the evolution of CO( 1 10)/Cr(002) texture, magnetic and physical grain size, intergrain-interaction, anisotropy, orientation ratio of remanence and coercivity were investigated experimentally. It is found that the hcp-Co(l10)hcc-Cr(002) texture is improved with increasing T, from 27OC to 265°C. The intergrain-interaction, magnetic and physical grain size decrease with increasing Ts and reach their minima at T,-265°C where the magnetic grain size is close to the physical grain size. The correlation between the film microstructure and magnetic properties is studied systematically.Index tems--Co( 1 lO)/Cr(OO2) texture, magnetic grain, intergraininteraction, x-ray rocking curve.

Low fly-height magnetoresistive ͑MR͒ sliders and low glide-height laser-texture thin film disks were introduced to meet the tribological challenges of proximity MR recording, with which an areal density of 5 Gb/in. 2 has been achieved when using the sliders with dual-stripe MR heads and the disks with low-noise media. The 30% pico sliders employed two air-bearing designs with a fly height around 12.5 nm. The thin film disks used superfinish substrates with a glide-avalanche-height falling well below 10.0 nm. In the contact start/stop ͑CSS͒ zones, small crater-shape laser texture bumps were generated to meet both low stiction and low glide-height requirements. An 80 Å thin amorphous nitrogenated carbon was added over the magnetic layers as a protective overcoat. A layer of perfluoropolyether with an additive of phosphazene compounds was applied on the disk surface to improve the reliability of head-disk interfaces. The near contact head-disk interface survived for 20 k-cycle hot/wet and hot/dry CSS tests without wear and high stiction. Twenty-four-hour hot/wet park-stiction values after 20 k CSS cycles were within the acceptable range. Remarkably, thermal-asperity tests showed no hits by using the proximity heads on the ultralow glide-height thin film disks.

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