Measurements of the thermophysical properties of V2O5 pellets. (3rd January 2020) - Kim, Hyunki
The thermal properties of V2 O5 and W0.04 V2 O5 pellets with α-V2 O5 phase were investigated by measuring the specific heat and thermal diffusivity. Near 150°C, the specific heats of both pellets increased remarkably due to the metal-insulator transition (MIT) reported in α-V2 O5 thin films. In thermal diffusivity measurement, neither pellet showed a remarkable change in terms of strong electron-phonon interaction. The thermal diffusivity of the V2 O5 pellet was about 20% larger than that of the W0.04 V2 O5 pellet due to the increase of surface defects of the nanospheres and the boundaries between them. The thermal conductivities of the V2 O5 and W0.04 V2 O5 pellets calculated using thermal diffusivity and specific heat clearly revealed a remarkable change near 150°C. Over the whole temperature range, the thermal conductivity of the V2 O5 pellet was larger than that of W0.04 V2 O5, due to the thermal diffusivity. Above 150°C, the electronic thermal conductivity showed a significant increase in both pellets, which was attributed to the MIT in the V2 O5 and W0.04 V2 O5 pellets, and the transition temperatures (Tc ) of the pellets were 200 and 180°C, respectively.