Experimental Study of Long-Term Static Friction and Magnetic Slider/Disk Interplanar Separation

Capacitance between a slider and disk was measured to relate slider/disk interplanar separation to static friction. The parallel plate capacitance formula was used to convert the capacitance into separation with a resolution of less than 1 nm. Separation and coefficient of static friction (stiction) were measured using assorted lubricant thicknesses with and without bonding on polished and textured disks. Separation was measured during contact start/stop (CSS) and long term slider dwell times, after which static friction was measured. Polished disks had high stiction events with smaller separations during and after the stiction event, unlike textured disks. Long-term dwell studies showed the coefficient of static friction and slider micro descent (decrease in interplanar separation) to be greatest with greater lubricant thickness and polished disks. Static friction and separation with bonded and unlubricated disks were time independent.