抄録
The mechanism of superlow friction was believed to be due to the change in the topmost layer of the CNx surface in the wear track to a low-shear-strength layer by forming a graphite-like structure. However, the effects of nitrogen atoms in the CNx coating and the ambient N_2 gas on the transformation of the surface layers of CNx remain unclear. We investigated the relationship between the friction coefficient (μ) and the nitrogen concentration in the wear track. Only in the case of the wear track from material slid in N_2, did the N KLL/C KLL ratio decrease to almost zero and the μ became lower than 0.01 was detected by AES. On the other hand, in the Ar environment, the N KLL/C KLL ratio in the wear track was comparable to the as-deposited CNx, the μ became 0.03, and the IG position of Raman shift increased at most 3cm^<-1>.
