Measurement of a solid-state triple point at the metal-insulator transition in vanadium dioxide
Park, Jae Hyung
MetadataShow full item record
The first-ever accurate measurement of a solid-state triple point in vanadium dioxide was made by performing simultaneous optical and transport measurements on a purpose-built nanomechanical strain apparatus that actively controls the length of a single nanobeam with a nanometer precision. The nature of the metal-insulator transition (MIT) in vanadium dioxide remains unsettled due to the presence of more than one insulating phase near the transition point, an observation that neither Mott nor Peierls picture of the transition suffices to explain. The triple point in vanadium dioxide, which has not been located, is a key to constructing its intrinsic phase diagram, a fundamental ingredient in the analysis and interpretation of any study of the MIT. The striking result is that the triple point precisely is where the MIT occurs at zero stress. While the implication of the new findings is unclear, there is a little doubt they will be crucial ingredients to the correct theory of the MIT. The value and importance of working with a single-domain nanocrystal while actively applying controlled strain have been demonstrated. This approach to studying the phase transition may serve as an indispensable tool, a new paradigm, for mastering the physics of complicated phenomena in strongly correlated materials where strain plays a key role.
- Physics