Structural studies of nanoporous carbon produced from silicon carbide

X-ray diffraction and small-angle scattering study of nanoporous carbon sam ples prepared from polycrystalline alpha SiC and single-crystal 6H SiC is r eported. The distribution function of carbon nanoclusters in size was found . In alpha SiC samples, the small size (10- 12 Angstrom) of nanoclusters is combined with their high size uniformity. Graphite-like nanoclusters 30-60 Angstrom in size were found in samples of both types. In 6H SiC samples, s uch clusters make up a notable fraction of the volume. The experimentally o bserved structural anisotropy of the samples is discussed. (C) 1999 America n Institute of Physics. [S1063-7834(99)03505-4].