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

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 SiCxO4 − x tetrahedra. Nanoscale clustering of SiCxO4 − 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.