Microstructure and Tribological Properties of C/N Co-Doping MoS₂ Composite Film

In this study, the C/N co-doping MoS₂ composite films (MSCN) with different sputtering power applied on graphite target were deposited by radio frequency magnetron sputtering of graphite and MoS₂ targets in argon and nitrogen atmosphere. The influence of C/N co-doping on microstructure, mechanical and tribological properties of deposited films was analyzed using the various analytical techniques. The results show that increasing the sputtering power applied on graphite target led to the increase of carbon concentration in the MSCN composite films, resulting in the formation of dense structure and smooth surface. When the graphite target sputtering power reached 350 W, a self-assembled multilayer structure with periodicity in the nanometer scale formed. Benefiting from the compact and self-assembled multilayer structure, the maximum hardness of MSCN film reached up to 9.76 GPa, and corresponding friction experiment indicates that comparing to pure MoS₂ film the composite films exhibited lower friction coefficient and high wear resistance both in high vacuum and ambient air conditions.