Structure and topological characteristics of amorphous silicon oxycarbide networks: Results from Reverse Monte Carlo simulations

摘要

The connectivity and length scale of spatial clustering of the structural units and the resultant topological aspects of amorphous SiOC networks, characteristic of polymer derived ceramics, are studied using Reverse Monte Carlo simulation, constrained by experimental density, composition and relative concentrations of SiC_xO_(4 ? x) tetrahedra. Nanoscale clustering of SiC_xO_(4 ? x) structural units results from mutual avoidance in connectivity between the constituent tetrahedra and the corresponding inefficiency in packing gives rise to a mass-fractal spatial distribution of the tetrahedra with a dimensionality of ~2.5.