Microscopic struture of amorphous covalent alloys probed by ab initio molecular dynamics: SiC

We performed ab initio molecular-dynamics simulations on an equimolar Si-C amorphous alloy. a-SiC is found not to exhibit chemical order and to be much complex than commonly believed. Our simulation is in good agreement with most measurements, although many interpretations of experimental data disagree with our results. The reasons for this discrepancy are analyzed and it is proposed that neutron scattering experiments can resolve the issue. Our study highlights the importance of reliable techniques complementary to experiment for a full characterization of amorphous semiconducting alloys. © 1992 The American Physical Society.