Pyrolysis of CH3CN . BCl3 at ca. 900-1000 degrees C over Co powder gen
erates novel graphitic BxCyNz nanofibres and nanotubes possessing a ra
nge of morphologies (e.g, curled, branched and bent). In these experim
ents the metal particles play an important role in the growth since na
notube formation appears to occur at the metal surface. High resolutio
n electron microscopy (HRTEM) and electron energy loss spectroscopy (E
ELS) studies suggest that the stoichiometry of the filaments is ca. [B
C2Nz](n) (z = 0.3-0.6). Higher relative concentrations of carbon occur
at the tips where the metal particle is found. A possible growth mech
anism for these new materials is proposed.