The effect of temperature on the properties of hydrothermally synthesized VO2 nanostructures and electro-induced MIT

Abstract

Vanadium dioxide (VO2) will undergo a reversible phase transition when under thermal, electrical or optical stimuli. The use of electric field to induce the transport properties is promising for novel switches, volatile memory and photodetectors. In this paper, VO2 nanoparticles were synthesized by the hydrothermal and post-vacuum annealing method. And then, the electro-induced MIT of the composite film filled with VO2 particles was discussed. The results show that purity VO2 (B) with different morphologies were obtained at different temperatures from 120 to 240 °C. The HRTEM images proved that the VO2 (B) nanobelts grow in the direction of the (110) plane, and the VO2 (M) nanoparticles grow along the (110) crystal plane. SEM pictures illustrate that the length of the nanoparticles becomes smaller as the preparation temperature increases. DSC reports and I-V traces proved that the VO2 (M) has an excellent performance of phase transition under heating and voltage. The results show that the hydrothermal temperature is helpful to increase the initial resistance, resistance change rate and phase change voltage of VO2 composite film. And the maximum resistance change rate before and after the MIT of samples is higher than 200. The experimental results show that the VO2 coating has an excellent voltage nonlinear response, due to the apparent switching performance, high nonlinear coefficient, and good consistency. The research data and theoretical analysis of this paper have an excellent guiding role for the application of VO2 in the electro-induced phase transition.