Temperature and Voltage Driven Tunable Metal-Insulator Transition in Individual $W_{x}V_{1-x}O_{2}$ nanowires

Abstract

Results from transport measurements in individual $W_{x}V_{1-x}O_{2}$ nanowires with varying extents of $W$ doping are presented. An abrupt thermally driven metal-insulator transition (MIT) is observed in these wires and the transition temperature decreases with increasing $W$ content at a pronounced rate of - (48-56) K/$at.%W$, suggesting a significant alteration of the phase diagram from the bulk. These nanowires can also be driven through a voltage-driven MIT and the temperature dependence of the insulator to metal and metal to insulator switchings are studied. While driving from an insulator to metal, the threshold voltage at which the MIT occurs follows an exponential temperature dependence ($V_{TH\uparrow}\propto\exp(\nicefrac{-T}{T_{0}})) $whereas driving from a metal to insulator, the threshold voltage follows $V_{TH\downarrow}\propto\sqrt{T_{c}-T}$ and the implications of these results are discussed.