Strain-Induced Modulation of Resistive Switching Temperature in Epitaxial VO₂ Thin Films on Flexible Synthetic Mica

The resistive switching temperature associated with the metal-insulator transition (MIT) of epitaxial VO₂ thin films grown on flexible synthetic mica was modulated by bending stress. The resistive switching temperature of polycrystalline VO₂ and V₂O₅ thin films, initially grown on synthetic mica without a buffer layer, was observed not to shift with bending stress. By inserting a SnO₂ buffer layer, epitaxial growth of the VO₂ (010) thin film was achieved, and the MIT temperature was found to vary with the bending stress. Thus, it was revealed that the bending response of the VO₂ thin film depends on the presence or absence of the SnO₂ buffer layer. The bending stress applied a maximum in-plane tensile strain of 0.077%, resulting in a high-temperature shift of 2.3 °C during heating and 1.8 °C during cooling. After 10⁴ bending cycles at a radius of curvature R = 10 mm, it was demonstrated that the epitaxial VO₂ thin film exhibits resistive switching temperature associated with MIT.