Preparation of carbon nitride films from g-C3N4 by ion-beam-assisted deposition

Abstract

Carbon nitride has noteworthy properties including high hardness levels. If the c-C3N4 or β-C3N4 structure can be synthesized, then hardness levels higher than that of diamond can be obtained. It is important to clarify the effect of ion impact on the growth of crystalline carbon nitrides on the synthesis of super-hard carbon nitrides. The ion beam-assisted deposition (IBAD) technique provides independent control over parameters, such as ion energy, temperature, and arrival rate of the atomic species during deposition. In this study, we investigated the structure and composition of a carbon nitride film prepared using graphitic carbon nitride as the evaporation source for the IBAD. The graphitic carbon nitride was formed into a pellet by press molding. The film deposited without nitrogen ion beam was obtained by evaporation using the pellet molded at 200 °C and 300 °C as the evaporation source. An amorphous carbon nitride film was obtained by IBAD using g-C3N4 as the evaporation source. The main chemical bonding in the carbon nitride film changed from C-N=C to C-C by varying the acceleration voltage of the nitrogen ion beam. Accordingly, the hardness of the film was increased. The hardness of the film at an acceleration voltage of 500 V was 23 GPa. This is due to the breaking of the CN bond by the ion beam, depending on the acceleration voltage of the ion beam.

Keywords

• carbon nitride film
• ibad
• electron beam deposition
• ion beam
• hardness