Effect of Strain on Properties of Metal Doped VO2 Based Thermal Sensors on Muscovite Substrate

Abstract

In this work, VO2 based thermal sensing thin film synthesized on flexible muscovite substrates by direct oxidation of deposited vanadium metal, were investigated for the impact of doping and strain on their electrical properties. We investigated both undoped and Ti doped VO2 on muscovite substrate and compared with those on Quartz substrate. Both doped and undoped VO2 were found to undergo phase transition due to effect of heat as well as mechanical strain on muscovite substrate. On the other hand, the Ti doped VO2, on both quartz and muscovite substrate showed significant reduction in the transition temperature compared to the undoped VO2 thin films on these two substrates. When subjected to mechanical strain, the VO2 thin film on muscovite substrates resulted in a decrease or an increase in resistance depending on whether the applied strain was tensile or compressive, respectively. The resistance change was also steeper around the transition temperature compared to room temperature, exhibiting high gauge factor. This metal doped VO2 on flexible muscovite substrate has the significantly low transition temperature which causes the VO2 film to undergo phase transition at a near-room temperature and enables it to be used as a temperature sensor with enhanced sensitivity.