PURPOSE: To slowly increase the bonding property of a carbon protective film to a lubricant by coating the top of the protective film with perfluoro-polyether having a functional group as the lubricant and carrying out warming under ultraviolet ray (UV) having low energy wavelength not enough to break the bond between carbon atoms.
CONSTITUTION: A carbon protective layer 4 is formed on each thin film magnetic layer 3 by sputtering and the top of the protective layer 4 is coated with a lubricative layer 5 of perfluoro-polyether having a functional group at least one terminal. The resultant magnetic medium is warmed while irradiating the surface of the lubricative layer 5 with UV in the wavelength region of 250-260nm. The warming is carried out by heating an inert atmosphere around the medium to 40-100°C or irradiating the surface of the medium with IR preferably in the long wavelength region of 1-5μm. Since the wavelength region of UV is limited to 250-260nm as a low energy region, the bond between carbon atoms is hardly broken. Energy not enough to break the bond can be replenished by warming the medium, the breaking of the bond proceeds slowly and bonding property to the terminal functional group of the lubricant is slowly increased.
ITO YOSHIAKI
ONODERA KATSUMI
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