超高記録密度磁気ディスクの単層グラフェン保護膜用潤滑油の耐熱性

抄録

Heat-resistance of lubricants (Perfluorinated polyether system) for HAMR (Heat-Assisted Magnetic Recording) system of HDD was examined using Near Infrared Raman Spectroscopy (NIRRS) and Surface-Enhanced Raman Spectroscopy (SERS). Heating of lubricant creates fluorescence which disturbs Raman analysis as a result of thermal degradation. NIRRS with 1064nm laser in wavelength is useful to analyze Raman spectrum of heated lubricant because there is no fluorescence in that wavelength region. Another method to avoid fluorescence disturbance is SERS, because enhanced Raman intensity is much larger than fluorescence intensity. As a result, Demnum type backbone structure, C₃F₆O-, is thermally stronger than Fomblin type backbone, -C₂F₄O-. Also, phenyl group improves heat-resistance of lubricant. Lubricant with OH groups and with three or six phenyl groups exhibits high heat-resistance over 250℃. A lot of unknown peaks are observed for lubricant with fluorescence. There peaks are decomposed by-products by heating. Carbon peaks are also observed for decomposed lubricants. Carbonization also occurred by thermal decomposition. Those by-products may create smear which causes head crushing.