Reduction of the TiO2-x melting temperature induced by oxygen deficiency with implications on experimental data accuracy and structural transition processes

Molecular dynamics simulations show a clear reduction of the melting temperature of rutile TiO2 induced by O deficiency. The observed effect is considerably stronger than reported in the experimental literature. This difference may be caused by a lack of knowledge of the O content at the melting point during experiments. In combination with temperature induced reduction, the melting temperature reduction poses questions about the process of Magneli phase formation in TiO2 memristor devices. Using TiO2 as a model for transition metal oxide ceramics, we propose a mechanism for the flash sintering process. [GRAPHICS] Time evolution of the Ti-Ti g(r) at 2500 K at 6.9% and 9,3% O deficiency during MD simulation at the 0 K volume. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim