Study of Perfluoropolyether Lubricant Consumption and Recovery in Heat Assisted Magnetic Recording Using Molecular Dynamics Simulation Method

Abstract

Currently, heat-assisted magnetic recording (HAMR) technology has been proposed as a method for enabling higher storage density. In this paper, the molecular dynamic simulation method was used to investigate the consumption and recovery of the lubricant perfluoropolyether (PFPE) layer under rapid heating and cooling through HAMR. A full-atom model for the 3-D slider-lubricants-disk substrate system was built for this paper. The lubricant adheres to the diamond-like carbon substrate, and the space between the slider and the lubricant is filled with helium atoms. It is found that HAMR laser heating results in the gradual consumption of the PFPE lubricant, and that the target operational temperature $T_{0}$ significantly affects the consumption of the PFPE lubricant on the disk substrate. The extent of lubricant consumption increases sharply when $T_{0}$ is above 600 K. The lubricant’s weight percentage on the disk substrate rises up again when cooling occurs. But it cannot be completely recovered. On the other hand, the bearing pressure reduces the degree of consumption of the PFPE lubricant by laser heating. However, the effect of bearing pressure on the amount of remaining PFPE lubricant becomes weak when $T_{0}$ is above 800 K.