Smear and Decomposition Behaviors of PFPE Lubricant Film on Magnetic Disk by Laser Heating in Air and Helium

Abstract

In HAMR system, the lubricant and DLC films are heated to 300–500 °C by laser irradiation, then the thermal reliability of these films and slider smear which is evaporated, thermally decomposed lubricant, or the contamination are critical issues. In this study, we compared the smear amount and the lubricant depletion of disks due to laser heating in air and helium environments using our developed pin-on-disk tester. The evaporated lubricants as smears adhered to a glass pin surface placed 5 µm above the disk. As the results, the amount of smear in helium is more than that in air at high temperatures, but the lubricant depletion in helium was similar to or less than that in air. The dominant mechanisms of lubricant depletion at high temperatures in air and He are decomposition and evaporation/desorption, respectively, determined by TOF-SIMS analysis.