Thermal Conductivity of VO₂ Nanowires at Metal-Insulator Transition Temperature

Vanadium dioxide (VO₂) nanowires endowed with a dramatic metal-insulator transition have attracted enormous attention. Here, the thermal conductance of VO₂ nanowires with different sizes, measured using the thermal bridge method, is reported. A size-dependent thermal conductivity was observed where the thicker nanowire showed a higher thermal conductivity. Meanwhile, the thermal conductivity jump at metal-insulator transition temperature was measured to be much higher in the thicker samples. The dominant heat carriers were phonons both at the metallic and the insulating regimes in the measured samples, which may result from the coexistence of metal and insulator phases at high temperature. Our results provide a window into exploring the mechanism of the metal-insulator transition of VO₂ nanowires.