The microstructure, mechanical and tribological properties of a-C:H films with self-assembled carbon nanohoops

Carbon nanohoops with unique structure and potential applications have successfully attracted attention from the fields of chemistry and material science. However, synthesizing carbon nanohoops is still a great challenge. Currently, we report hydrogenated amorphous carbon films with spontaneously forming carbon nanohoops were prepared through radio frequency (R.F) magnetron sputtering deposition, and the content of carbon nanohoops in the films was adjusted by varying R.F power. Raman spectroscopy and high resolution transmission electron microscopy were used to determine the formation of carbon nanohoops. It was found that the tribological and mechanical performances of the films depended on the content of carbon nanohoops in the films. The film with the maximum relative content of carbon nanohoops exhibits a low friction coefficient (0.028) and a low wear rate (3.54 × 10− 7 mm3/Nm) as well as a high elastic recovery (66%).