Strain-Induced Self Organization of Metal−Insulator Domains in

We investigated the effect of substrate-induced strain on the metal−insulator transition (MIT) in single-crystalline VO2 nanobeams. A simple nanobeam−substrate adhesion leads to uniaxial strain along the nanobeam length because of the nanobeam’s unique morphology. The strain changes the relative stability of the metal (M) and insulator (I) phases and leads to spontaneous formation of periodic, alternating M−I domain patterns during the MIT. The spatial periodicity of the M−I domains can be modified by changing the nanobeam thickness and the Young’s modulus of the substrate. Many unique properties of transition metal oxides, including ferroelectricity,1,2 colossal magnetoresistivity,3-5 and high-TC superconductivity,6 originate from the interplay between structural phase transitions and nanoscale electronic and magnetic ordering. Lattice strain, which affects the relative stability of competing structural phases, thus has a profound influence on the electrical, optical, and magnetic properties of these oxides.1-6 Coherent strain generated from epitaxial growth can result in spontaneous formation of domai