Crystallinity and In-plane Atomic Arrangement of Graphite-like Layered Material, BC₆N

Abstract

Crystallinity of a graphite-like layered material, BC₆N was evaluated by X-ray diffraction and Raman spectroscopy. The in-plane atomic arrangement of the material was estimated by using a semi-empirical molecular orbital calculation. The BC₆N prepared by CVD (Chemical Vapor Deposition) at 1800°C had the crystallite size Lc of 9.68nm which was much larger than that of BC₆N₂ previously prepared by the pyrolysis of the adduct, (CH₂CHCN) ₂: BCl₃. On the other hand, the BC₆N showed a broad Raman spectrum with a large D-band. This is explained by the alloying of B and Natoms in the graphite network, which introduced the variety of chemical bonds and diminished the size of graphite crystals. Among the calculated 10 types of the atomic arrangements, 2 candidates are the most favorable for the BC₆N prepared in this study from the standpoint of the topology based on the chemical reaction. Thermodynamically stable arrangements would be made by the reaction at higher temperature or by using the physical enhancement, which could break the precursors into atomic species.