Dynamic Performance of Head–Disk Interface in HAMR Using Molecular Dynamics Simulation Method

摘要

Heat-assisted magnetic recording (HAMR) technology is a great way to achieve higher storage density. In HAMR, dynamic performance of the head-disk interface (HDI) is critically important for the read/write stability. Lubricant bridge formation and lubricant transfer can significantly deteriorate HDI performance. In this paper, a 3-D full-atom model of a slider-lubricant-disk substrate system is established to study the dynamic performance of HDI in HAMR. The overlayers of the slider and disk substrate are made of diamondlike carbon, and the main lubricating ingredient is perfluoropolyether (PFPE). The formation and breaking of the lubricant bridge are investigated with the slider moving up and down. It is found that during the moving down process, PFPE molecules escape from the lubricant layer, and a lubricant bridge between the slider and disk is formed. During the moving up process, the lubricant bridge becomes thin and eventually breaks. The stable value of PFPE weight percentage on the slider during the moving up process is always larger than that during the moving down process. This is because of easier transfer of lubricant molecules to the slider in the low flying height region. The formation height is smaller than the breaking height, but these values are closer when the operational temperature is higher.