Synthesis and properties of B_xC_yN_z coatings

Some of the most interesting compounds from both technological and a scientific viewpoint can be found within the B–C–N composition triangle. Despite all the attention that some phases on the vertices and sides of the triangle have attracted, few works have focused inside the triangle itself. A laser-assisted chemical vapor deposition system was used to deposit B–C–N phases over fused quartz substrates. Two sets of gaseous precursors were used, namely B₂H₆ + NH₃ + C₂H₄ and B₂H₆ + (CH₃)₂NH. The coatings were characterized regarding chemical composition, structure, and morphology. Hardness measurements were also carried out with a depth-sensing indentation instrument. It was found that depending on the gas phase, different regions of the BCN solid composition triangle are accessed. Coatings ranging from pure h-BN to pure B₄C were obtained, as well as mixtures of these with B_xC_yN_z compounds.