Mesoscopic electronic heterogeneities in the transport properties of V2O3 thin films

The spectacular metal-to-insulator transition of V2O3 can be progressively suppressed in thin film samples. Evidence for phase separation was observed using microbridges as a mesoscopic probe of transport properties, where the same film possesses domains that exhibit a metal-to-insulator transition with clear first-order features or remain metallic down to low temperatures. A simple model consisting of two parallel resistors can be used to quantify a phase coexistence scenario explaining the measured macroscopic transport properties. The interaction between film and substrate is the most plausible candidate to explain this extended phase coexistence, as shown by a correlation between the transport properties and the structural data.