Synthesis and characterization of boron-substituted carbons

Thin films of boron-substituted carbons have been synthesized by chemical v apor deposition. X-ray diffraction measurements showed that the d((002)) va lue depends both on B at.% in the deposits and on the reaction temperature. Addition of boron increases the crystallinity up to a certain boron concen tration, but beyond this critical value, on the contrary, the crystallinity deteriorates as the boron content increases. B-11-NMR indicated that isola ted boron atoms are dominant at low boron concentration in the deposits, an d that the number of boron-to-boron connected atoms increases rapidly when the boron content is higher. (C) 2000 Elsevier Science Ltd. All rights rese rved.