Boron carbide thin films were synthesised by laser-assisted chemical vapour
deposition (LCVD), using a CO2 laser beam and boron trichloride and methan
e as precursors. Boron and carbon contents were measured by electron probe
microanalysis (EPMA). Microstructural analysis was carried out by Raman mic
rospectroscopy and glancing-incidence X-ray diffraction (GIXRD) was used to
study the crystallographic structure and to determine the lattice paramete
rs of the polycrystalline films. The rhombohedral-hexagonal boron carbide c
rystal lattice constants were plotted as a function of the carbon content,
and the non-linear behaviour observed was interpreted on the basis of the c
omplex structure of boron carbide. (C) 2000 Elsevier Science S.A. All right
s reserved.