Examination of the atomic pair distribution function (PDF) of SiC nanocrystals by in-situ high pressure diffraction

摘要

X-ray and neutron diffraction experiments were performed on nanocrystalline SiC with the average grain diameters of 7, 12, and 16nm subjected to isostatic pressure. Under pressure the interatomic distances undergo a complex, non-monotonic changes which were correlated with the compression of the SiC lattice determined from the Bragg scattering. The results indicate the presence of non-uniform distribution of stresses between the interior and surface shell of the nanograins. The present results lend a strong support to the concept of a core-shell model of nanocrystals.