The mechanical, tribological and optical properties of CNx coatings prepared by sputtering methods

Abstract CN x coatings were prepared by DC magnetron sputtering at different N 2 pressures. Increase of N 2 pressure led to the increase of nitrogen content N/C in the films, but decreased their microhardness. Evaluation of optical properties and electron-energy-loss function combining spectroscopic ellipsometry (1.5–4 eV) and VUV reflection spectroscopy (4–14 eV) by means of Kramers-Kronig analysis showed increase of the π-plasmon resonance peak, which indicates enhancement of the amount of π-bonded electrons. It demonstrates increase of sp 2 hybridization. The extrapolated energy gap indicates more semimetallic properties of the CN x films due to nitrogenation.