Lube Depletion Caused by Thermal-Desorption in Heat Assisted Magnetic Recording

Heat assisted magnetic recording is a promising technique to overcome the superparamagnetic limit. However, it brings about serious problems to the slider-disk interface. One of the problems is lube depletion on disk surface caused by laser heating. In this work, the process of lube depletion caused by lube desorption during laser heating is explained. The effects of lube molecular weight, laser heating temperature, slider air-bearing pressure, etc. on the lube depletion are studied. It is found that lube thinning rate at disk surface decreases dramatically with the increase in lube molecular weight. It is a possible solution to overcome the lube depletion problem by using high molecular weight lube. Lube thinning rate can also be decreased significantly by lowering laser heating temperature, lowering slider air-bearing pressure over the laser heating area, and lowering lube vapor pressure.