where Dhkl is the crystallite size, λ is the X-ray wavelength 1.5406 Å Cu, β is full width at half-maximum (FWHM) and θ is the angle reflection of (111) direction. The crystallite sizes of all films are relatively small in comparison to the values of other transition metal compounds such as TiN, TiC and CrN, having a grain size in the range 9–18 nm depending on the nitrogen partial pressure. The calculated grain sizes and the lattice parameters from (111) diffraction peak are shown in Fig. 2.