抄録
The superlow friction mechanism of CNx (Carbon Nitride) coating slid against Si_3N_4 ball in N_2 gas was suggested to be taken place when the topmost surface of CNx changed to graphitic structure. It was assumed that ultraviolet ray (UV) could break C-N single bond when the ray power exceeded C-N single bonding energy, and we hypothesized that UV irradiation could make the CNx coating topmost surface graphitic without friction in N_2 gas. We carried out preparing the CNx coating irradiated UV as 254, 312 and 356 nm wavelength in air, Ar, N_2 and O_2. These specimens were analyzed by AES and XPS, It was found that the average N/C ratio of CNx films ultraviolet irradiation in O_2 was reduced by 60 percent. N-C and N=C were reduced to half, N-N/N-O was not changed. From AFM images, there was no effect of etching with ozone generated by the UV excitation of oxygen.
