A SAXS study of the precipitation of nano-clusters in Si-C amorphous films

The structural evolution of amorphous Si-C films, which were prepared by floating a polycarbosilane solution on water and heat-treated at the temperatures 700, 800, 900 and 1000 °C, was investigated by small-angle X-ray scattering (SAXS). The isotropic SAXS profile for the Si-C films can be decomposed to two parts of scattering patterns, one has a sharp increase at h < 0.07 Å−1 and the other has a broad maximum at about h = 0.3 Å−1 in the same manner as for Si-C fibres. The Vickers hardness of the films is correlated to the characteristic variations in their medium-range structure.