Strain engineering of optical properties in transparent VO₂/muscovite heterostructures

Transparent VO₂/muscovite heterostructures have attracted considerable attention because of their unique chemical and physical properties and potential practical applications. In this paper, we investigated the influence of uniaxial mechanical strain on the optical properties of VO₂/muscovite heterostructures through Raman scattering and optical transmittance measurements. Under applied strain, linear shifts in peak positions of Raman-active phonon modes at approximately 340, 309, and 391 cm^-1 were observed. The extracted Grüneisen parameter values were approximately between 0.44 and 0.57. Furthermore, a pronounced strain-induced change in the metal-insulator transition (MIT) temperature was observed, which decreased under compressive strain and increased under tensile strain. The rates of MIT temperature variation reached 4.5 °C per % and 7.1 °C per % at a wavelength of 1200 nm during heating and cooling processes, respectively. These results demonstrate that the modulation of the optical properties of VO₂/muscovite heterostructures is controllable and reversible through strain engineering, opening up new opportunities for applications in flexible and tunable photonic devices.