Modelling and simulation of the lubricant depletion process induced by laser heating in heat-assisted magnetic recording system

A model for lubricant flow dynamics under a scanning laser beam has been constructed for a heat-assisted magnetic recording system. The effects of evaporation, thermocapillary stress and thermoviscosity on the lubricant depletion on both glass and aluminium disks are systematically studied. Our results indicate that both evaporation and thermocapillary stress are able to deplete non-negligible amount of Z-type PFPE lubricants with a low molecular weight from the disk surface within nanoseconds. Evaporation is the dominant lubricant removal mechanism when low molecular weight lubricant is used. Evaporation is significantly reduced when high molecular weight PFPE lubricants are used. Our simulations show that the performance of head/disk interface of heat-assisted magnetic recording systems may be significantly deteriorated when lubricants with improper properties are used.