Reactive Molecular Dynamics Study of Effect of Water and Oxygen Molecules on Decomposition of PFPE Lubricant Films in Heat-Assisted Magnetic Recording

Abstract

To realize heat-assisted magnetic recording (HAMR), which can largely increase the recording density of hard disk drives, it is crucial to ensure the reliability and durability of the head disk interface (HDI) that involves high temperature and high-speed shear. In this study, we performed reactive molecular dynamics simulations to clarify the effects of water and oxygen molecules on the decomposition of nanometer-thick perfluoropolyether D-4OH films that lubricate the HDI of HAMR. From the simulation results, we found that water molecules accelerate the decomposition of D-4OH and this effect is suppressed by the presence of oxygen molecules. We also found that high normal pressures and concentrations of water and oxygen molecules lead to fast decomposition of D-4OH molecules.