Atomic mechanism of predictable phase transition in dual-phase H₂Ti₃O₇/TiO₂ (B) nanofiber: an in situ heating TEM investigation

The phase transition from H₂Ti₃O₇ to TiO₂ (B) in a 1D single nanocrystal of H₂Ti₃O₇ was observed by in situ heating in a transmission electron microscope experimentally. The results indicate a typical monoclinic-to-monoclinic crystallographic orientation relationship between the two phases. Moreover, the fundamental building blocks and invariant deformation element model were both adopted to reveal the atomic mechanism and predict the crystallographic orientation relationship quantitatively for the phase transition. The prediction was precisely consistent with TEM results. Some like it hot: The predictable phase transition from H₂Ti₃O₇ to TiO₂ (B) in a 1D single-crystal nanofiber has been investigated by in situ heating during TEM (see figure). The results show a typical monoclinic-to-monoclinic relationship between the two phases, and the prediction of the crystallographic orientation relationship is precisely consistent with the TEM observations.