Nanotextured phase coexistence in the correlated insulator v 2 O 3

The insulator-metal transition remains among the most studied phenomena in correlated electron physics. However, the spontaneous formation of spatial patterns amidst insulator-metal phase coexistence remains poorly explored on the meso- and nanoscales. Here we present real-space evolution of the insulator-metal transition in a V 2 O 3 thin film imaged at high spatial resolution by cryogenic near-field infrared microscopy. We resolve spontaneously nanotextured coexistence of metal and correlated Mott insulator phases near the insulator-metal transition (1/4160-180 K) associated with percolation and an underlying structural phase transition. Augmented with macroscopic temperature-resolved X-ray diffraction measurements of the same film, a quantitative analysis of nano-infrared images acquired across the transition suggests decoupling of electronic and structural transformations. Persistent low-temperature metallicity is accompanied by unconventional critical behaviour, implicating the long-range Coulomb interaction as a driving force through the film's first-order insulator-metal transition.