First principles investigation of the surface stability and equilibrium morphology of MoO_3

摘要

The surface stability and equilibrium morphology of MoO3 were investigated by the first principles calculations. The thermodynamic energies of the stoichiometric surfaces of MoO3 are in the order (0 1 0) (1 01) (0 0 1) (1 00). It is found that the (0 1 0) surface has a lowest surface energy, which agrees well with the previous calculations. The energies of the non-stoichiometric surfaces were evaluated as functions of temperature and oxygen partial pressure. The results show that the energies of Mo-terminated surfaces decrease with temperatures, and increase with oxygen partial pressures, while the energies of O-terminated surfaces show the opposite rule. The equilibrium morphology of MoO3 was predicted by using the Gibbs-Wulff model, and then was compared with the other's experiments and theoretical results.