Thermal Conductivity of VO2 Nanowires at Metal-Insulator Transition Temperature

Abstract

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.

Remote Monitoring of Skin Temperature Through a Wristband Employing a Printed VO Sensor

“…However, when the temperature is greater than TMIT, VO2 adopts a rutile structure (R-phase), which corresponds to a metallic state due to the linear arrangement of Vanadium (V-V) atoms, which is illustrated in Fig. 2(b) [34][35][36][37][38][39][40][41]. The change in the state of VO2 from an insulator to a conductor and vice versa makes it attractive for use in optical and electrical devices.…”

“…The change in the state of VO2 from an insulator to a conductor and vice versa makes it attractive for use in optical and electrical devices. As the VO2 (M) phase experiences the MIT at a temperature of 68°C [35], a highly sensitive temperature sensor can be realized near the MIT temperature. Since the TMIT of VO2 (M) (68°C) is relatively high compared to that of skin temperature (30°C to 40°C), it must be lowered to achieve higher sensitivity over the skin temperature range.…”

“…for radiofrequency (RF) switching applications [34][35][36][37][38]. In the literature, there is only one reported VO2-based temperature sensor, which was neither printed nor optimized for the skintemperature range [16].…”

Observation of Metal–Insulator Transition (MIT) in Vanadium Oxides V2O3 and VO2 in XRD, DSC and DC Experiments

“…As the MIT occurs in VO 2 at a temperature slightly higher than room temperature, its observation is relatively easy. The temperature dependency of the electronic resistivity of vanadium dioxide can be found in many papers, e.g., [37][38][39][40][41][42]. It is striking that even though some electrical data were provided by Morin in 1959 [33], most of the good-quality electrical measurements were published no earlier than 15 years ago.…”

Heat Transfer in Nanostructured Materials

“…Lv et al [ 2 ] developed a novel approach to enhance the thermal conductivity of graphene papers by depositing AgNWs on graphene sheets, resulting in a highly promising TIM with a cross-plane thermal conductivity of up to 7.48 W m −1 K −1 . Li et al [ 3 ] revealed size-dependent thermal conductivity in VO 2 nanowires that showed an increase in jump during metal-insulator transition temperature with increasing sample thickness. Phonons were identified as major carriers that dominate thermal transport in the nanowires.…”