The interface structures formation and their effectiveness for enhancement of the phase stability in Ti/Si binary oxide

Possible cluster models for the Ti/Si binary oxides were optimized with the density functional theory (DFT/B3LYP). The preferential structures are analyzed by the Gibbs free energy calculations and computational infrared vibration spectra. The theoretical results show that the formation of the interface structures is energetically feasible. Edge-shared interface structures form in the double tetrahedral clusters while corner-shared interface structures form in the triple tetrahedral clusters. The transformation of the interfacial structures makes the cluster structure to be correlated innovatively with the phase transformation of TiO(2). The crystal growing restraint for SiO(2)-doped TiO(2) mainly comes from the reduction in interfacial charge of oxygen atoms and the titanium atoms. Experimentally, Ti/Si binary oxides having different Ti contents were prepared by the sol-gel method with sequential hydrolysis. The Fourier infrared spectra of the oxide powders compared with computational infrared vibration spectrum confirmed the theoretical results. (C) 2010 Elsevier B.V. All rights reserved.