New filamentous deposits in the boron-carbon system Original Research Article

BCl3 and C6H6 were reacted near 1000 °C in the presence of hydrogen and nickel particles. Instead of the expected tubular filaments of the hexagonal BCx (x ≥ 3) phase, non tubular filaments with whisker-like morphology and structure were observed by transmission electron microscopy. Electron energy loss spectrometry demonstrated that their compositions were in the 50–75 at% boron range. Under the same experimental conditions but in the absence of nickel, layers of the expected boron substituted hexagonal carbon were deposited. Nickel seems therefore not only to catalyse the formation of acicular products but also to act on their composition.