Non-Equilibrium Spark Plasma Reactive Doping Enables Highly Adjustable Metal to Insulator Transitions and Improved Mechanical Stability for VO2

TL;DR

This paper introduces a rapid spark plasma reactive doping method for VO2 that allows precise control over its metal-insulator transition temperature and enhances its mechanical stability, enabling diverse practical applications.

Contribution

The study presents a novel SPARS technique for in situ doping and sintering of VO2, offering high flexibility in tuning electronic and mechanical properties within a short processing time.

Findings

Wide adjustment of TMIT and resistivity achieved

Mechanical strength of VO2 significantly improved

Dopant elements include Ti, W, Nb, Mo, Cr, Fe

Abstract

Although vanadium dioxide (VO2) exhibits the most abrupt metal to insulator transition (MIT) properties near room-temperature, the present regulation of their MIT functionalities is insufficient owing to the high complexity and susception associated with V4+. Herein, we demonstrate a spark plasma assisted reactive sintering (SPARS) approach to simultaneously achieve in situ doping and sintering of VO2 within largely short period (~10 minutes). This enables high convenience and flexibility in regulating the electronic structure of VO2 via dopant elements covering Ti, W, Nb, Mo, Cr and Fe, leading to a wide adjustment in their metal to insulator transition temperature (TMIT) and basic resistivity. Furthermore, the mechanical strengths of the doped-VO2 were meanwhile largely improved via the compositing effect of high melting-point dopant oxide. The high adjustability in MIT properties and improved mechanical properties further paves the way towards practical applications of VO2 in power electronics, thermochromism and infrared camouflage.