Head-disk lubricant transfer and reposition during heat assisted write and read operations

Heat Assisted Magnetic Recording (HAMR) is the most important of the next generation storage technologies that are currently competing to supplant perpendicular magnetic recording (PMR). Recently, HAMR has demonstrated one terabit per square inch (1 Tb/in²) recording density and extensibility of this new technology well beyond this density seems practical [1]. HAMR technology enhances the magnetic writing process by the inclusion of a strong optical field that propagates from the read-write head and instantaneously heats the magnetic recording layer to above its Curie temperature, thus allowing magnetic recording on media with ultrahigh magnetic anisotropy that otherwise could not be written with conventional writers. During HAMR writing, the HAMR media will experience ultra-rapid heating, reaching a peak temperature in excess of 500 C. These conditions will thermally stress the lubricant film on the media which, along with the carbon overcoat, protects the magnetic storage layer from environmental, thermal and tribological degradations. The cumulative effect of these repetitive heating cycles on the redistribution of the lubricant film of the media is a significant concern, due to the need to maintain a functioning lubricant film on the media and the negative effect on the head flyability with lubricant accumulation on its surface. The effect of these high temperature transients on the distribution of lubricant on both the media surface and the head are probed and specific rates of its accumulation and deposition are determined by varying the number of write cycles, laser-on durations, the head flying height (FH), and the peak surface temperature.