Formation of β-C3N4 Nanocrystals in Ti-Doped Carbon Nitride Films Prepared by Cathode Arc-Assisted Middle-Frequency Magnetron Sputtering

Ti-doped carbon nitride thin films have been deposited by cosputtering Ti and graphite targets in a mixed plasma of Ar and N. Transmission electron microscopy revealed that the nucleation of β-C3N4 could be promoted by Ti incorporation. The N content of the films was found to strongly depend on Ti concentration, even a small amount of Ti incorporation resulted in a drastic increase in N content. An evolution from amorphous layers with fine mixtures of C, N, and Ti to matrices embedded with β-C3N4 nanocrystals was observed with increasing bias voltage.