CRYSTAL-STRUCTURE OF NEW COMPOSITION BORON-RICH BORON-NITRIDE USING RAMAN-SPECTROSCOPY

The synthesis of polycrystalline boron nitride films, with beta-rhombohedral boron crystallites, was accomplished with BCl3-NH3-H-2 in a tungsten hot filament chemical vapor deposition apparatus. Raman spectra and XRD results revealed that the crystal structure of the boron nitride films is similar to rhombohedral boron carbide B4C. The composition of these crystallites by XPS was found to give a ratio of boron to nitrogen of 3:1. These results suggest that the boron nitride crystals obtained in this work are previously unreported compounds of a rhombohedral boron-rich boron nitride, analogous to boron carbide, B4C.