Synthesis and characterization of C3N4 hard films

C3N4 films have been synthesized on both Si and Pt substrates by microwave plasma chemical vapor deposition (MPCVD) method. X-ray spectra were calcula ted for single phase alpha-C3N4 and beta-C3N4 respectively. The experimenta l X-ray spectra of films deposited on both Si and Pt substrates showed all the strong peaks of alpha-C3N4 and beta-C3N4, so the films are mixtures of alpha-C3N4 and beta-C3N4. The N/C atomic ratio is in the range of 1.0-2.0. X-ray photoelectron spectroscopy (XPS) analysis indicated that the binding energy of C 1s and N 1s are 286.2 eV and 399.5 eV respectively, correspondi ng to polarized CN bond. Fourier transform infrared absorption (FT-IR) and Raman spectra support the existence of C-N covalent bond in the films. Nano -indentation hardness tests showed that the bulk modulus of a film deposite d on Pt is up to 349 GPa.