Effects of Molecularly Thin Liquid Lubricant Film Materials on Slider Hysteresis Instability in Hard Disk Drives

In this study, the difference in the touchdown and takeoff pressures was monitored by using three types of lubricant materials, namely, Zdol2000, Ztetraol2000 and A20H2000 by using the pump down pressure test. The results indicated that the touchdown pressures depended on the lubricant materials; it was greatest for Ztetraol2000 and smallest for A20H2000. The takeoff pressure was greater for a lubricant with lower mobility. Considering these experimental results, it was suggested that the variation in the touchdown pressure is due to a variation in the intermolecular forces, taking into account the lubricant pickup by a slider. Further, it was suggested that the variation in the takeoff pressure is caused by a variation in the friction forces between the slider and disk surface.