V and N co-doped diamond-like carbon films deposited by pulsed bias arc ion plating

V and N co-doped diamond-like carbon (DLC–VN) composite films were deposited on cemented carbide substrates by pulsed bias arc ion plating. The effects of V and N contents on the structures and properties of the films were investigated by X-ray photoelectron spectroscopy (XPS), Raman spectra, grazing incident X-ray diffraction (GIXRD), transmission electron microscopy (TEM) and nano-indentation, respectively. The as-deposited films consist of a DLC–VN nanocomposite, where VN nanograins are embedded in an amorphous carbon matrix. The V and N contents have significant influences on the relative proportion of VN with respect to DLC. A proper concentration of VN nanocrystals in DLC induces even the formation of nano-diamond. The DLC–VN films have higher hardnesses than pure DLC films, which could be attributed to the nanocomposite structure.