A Model for Laser Induced Lubricant Depletion in Heat-Assisted Magnetic Recording

The lubricant evaporation caused by the rapid laser heating is always a big concern in heat-assisted magnetic recording. In this article, we develop an empirical equation based on the existing measurement data to describe the relation between the evaporation coefficient of lubricant and temperature on the disk surface. The evaporation coefficient of lubricant is found to decrease from ~1.0 to ~0.003 for the temperature range from 406 to 512 K and follow the trend given by the Arrhenius formula. By incorporating this formula into a previously established evaporation model, we can get a new model, which enables us to predict the lubricant evaporation and depletion caused by the rapid laser heating more accurately than ever.