Emergent properties in films of transition metal oxides
ORAL
Abstract
Transition metal oxides exhibit diverse emergent phenomena such as strongly correlated Mott insulating states, magnetic and structural phase transitions, and metal-insulator transitions. Many of these emergent states occur at nanometer length scales which cannot be accessed with traditional infrared focusing methods due to the Abbe diffraction limit. However, scattering-type scanning near-field infrared microscopy (S-SNIM) can circumvent the Abbe diffraction limit and probe optical properties with spatial resolution of tens of nanometers. We have coupled table-top plasma light sources developed in-house to a commercial S-SNIM apparatus from Neaspec GmbH to demonstrate broadband infrared nano-spectroscopy. This is used to study the novel nanoscale properties of ultrathin vanadium dioxide (VO2) film on rutile titanium dioxide (TiO2) substrate. Due to strain from the substrate, the metal-insulator transition in the VO2 film occurs at a temperature of 305 K which is much lower than in bulk VO2. We also study the surface metallic layer induced by vacuum-annealing of insulating strontium titanate (SrTiO3) crystals and extract the dynamical properties of the free charge carriers.
*M.M.Q. acknowledges support from ETRI and the National Science Foundation (NSF).
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Presenters
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D. Lahneman
- Department of Physics, College of William & Mary
- Department of Physics, College of William and Mary