Effect of Size and Vacancy on Phase Transformation of Ti ₃ O ₅

Ti3O5 has an ultrafast and reversible metal-to-insulator phase transition, which can be induced in many ways. Although there are many studies, they are mainly focused on the heat, current, pressure, and laser phase transition pathway but ignore the phase transition induced by the size effect and vacancy. Here, we establish the volume–energy model of Ti3O5 nanograins and study the size threshold and influence factors of the phase transition from the energy point of view. In addition, we also investigated the influence of vacancy defects on the phase transformation of Ti3O5. Our work not only provides important insights into the Ti3O5 nanosize phase transition but also presents useful strategies and methods that can be used to handle other similar nanostructure phase transitions.