The Structural Phase Transition in Individual Vanadium Dioxide Nanoparticles

Vanadium dioxide (VO2) single crystals undergo a structural first-order metal to insulator phase transition at approximately 68 degrees C. This phase transition exhibits a resistivity change of up to 5 orders of magnitude in bulk specimens. We observe a 2-3 order of magnitude change in thin films of VO2. Individual particles with sizes ranging from 50 to 250 nm were studied by means of Transmission Electron Microscopy (TEM). The structural transition for individual particles was observed as a function of temperature. Furthermore, the interface between grains was also studied. We present our current progress in understanding this phase transition for polycrystalline thin Films of VO2 from the view of individual particles.