Synthesis, structure and mechanical properties of fullerene-like carbon nitride films deposited by DC magnetron sputtering

摘要

Carbon nitride (CN_x) films were deposited by direct current magnetron sputtering at different N_2 fractions and a substrate temperature of 450°C. The composition and microstructure of CN_x films were investigated by high resolution transmission electron microscopy, X-ray absorption near-edge spectroscopy, X-ray photoelectron spectroscopy and Raman spectroscopy. The CN_x films change from amorphous to fullerene-like nanostructure as the N_2 fraction is ranged from 0.05 to 0.1, and then to nitridized graphite nanocrystals in amorphous matrix at pure N_2, and the curvature of the basal planes decreases with the increase of N content in CN_x films. Meanwhile, the structural analysis provides the identification of spectral signatures related with the formation and promotion of FL arrangements, and the formation of C-sp~3 sites has been generally considered as the cross-linking path in fullerene-like CN_x. Their mechanical and tribological properties were also investigated in detail, aiming at illustrating excellent mechanical, friction and wear behaviours of the fullerene-like CN_x film with respect to its high hardness and elastic recovery and less dependence on humidity and oxygen as compared with the amorphous CN_x film.