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

TL;DR

This study investigates how temperature and voltage influence the metal-insulator transition in individual W_xV_{1-x}O_{2} nanowires, revealing doping-dependent transition temperatures and distinct voltage-driven switching behaviors.

Contribution

It provides new insights into the doping-dependent phase diagram and voltage-driven transition mechanisms in nanowire-based VO2 systems, extending understanding beyond bulk materials.

Findings

Transition temperature decreases with W doping at -48 to -56 K per atomic percent W.

Voltage-driven MIT exhibits exponential and square-root temperature dependencies for different switching directions.

Nanowires show tunable MIT characteristics influenced by W doping and applied voltage.

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.