Structural and tribological behaviors of graphene nanocrystallited carbon nitride filmsViews [1509] Delivery time :2019-08-13 13:21:48

Structural and tribological behaviors of graphene nanocrystallited carbon nitride films

Applied Surface Science 495 (2019) 143591

Pengfei Wang, Peidong Xue, Cheng Chen, Dongfeng Diao*

Structural and tribological performances of graphene nanocrystallited carbon nitride (GNCN) films were investigated. The GNCN films were prepared in a multifunctional electron cyclotron resonance plasma system with the variation of the microwave power from 300 to 700 W. An increase in the growth rate and a decrease in the nitrogen atomic concentration were clearly observed with increasing microwave power. Whereas, the residual stress, surface roughness (Ra), and nano-scratch depth of the GNCN films were independent of the microwave power. Raman and XPS characterizations of the GNCN films indicated a gradual increase in sp2 carbon bonding structures as well as the size of the graphene nanocrystallite. When rubbing against the Si3N4 balls, low friction coefficients of approximately 0.05 were achieved in nitrogen gas atmosphere. Low friction was attributed to the formation of a uniform tribofilm on the wear scar of the worn Si3N4 ball surface. TEM-EELS analysis of the transfer film evidenced the formation of graphene nanocrystallites and the loss of nitrogen atoms in the topmost layer. It is strongly argued that the evolution of carbon sp2 structure on the contact interface is favorable for obtaining low friction coefficient of the GNCN films in nitrogen gas environment.