Preparation and characterization of nanocrystalline composites Mo–C–N hard films

Abstract Molybdenum carbonitride (MoCN) films were deposited on Si (001) and stainless steel substrates by reactive direct-current magnetron sputtering with a molybdenum and graphite composite target. By changing the substrate temperature and the N2 / Ar ratio in the sputtering gas, it is found that good quality MoCN films can be deposited at substrate temperature of 300–400 °C under N2 partial pressure of 0.25–0.5 Pa with a total working pressure of 1 Pa. The structures of the films deposited at such conditions were determined by X-ray diffraction and X-ray photoelectron spectroscopy analysis as nanocrystalline molybdenum carbonitride with a grain size of several ten nanometers was embedded in the amorphous matrix of C and CNx. The hardness of the MoCN films can reach 28 GPa, much higher than the value of MoC and MoN films alone.