Modeling laser induced lubricant depletion in heat-assisted-magnetic recording systems using a multiple-layered disk structure

In this paper, we model the depletion of lubricant from a disk surface subject to heating by a scanning laser in a heat assisted magnetic recording (HAMR) system. A multi-layer disk structure is used consisting of the substrate (either glass or aluminum), the CoFe based soft magnetic under- layer, a Ru based intermediate layer, a CoCrPt based recording layer, the diamond-like-carbon layer, and the lubricant film. The thickness and material properties of the different layers are shown to play an important role in the conduction of heat from the top layer to the bottom layer and, consequently, in the lubricant depletion process due to heating by a scanning laser. The results show that it is critical to include realistic multi-layer disk structures in HAMR lubricant depletion modeling.