Authors: Hyunki Kim; Soo Yeol Jeong; Yeon Suk Choi; Sok Won Kim
Addresses: Department of Physics, University of Ulsan, Ulsan 680-749, South Korea ' Korea Basic Science Institute, Daejeon 169-148, South Korea ' Korea Basic Science Institute, Daejeon 169-148, South Korea ' Department of Physics, University of Ulsan, Ulsan 680-749, South Korea
Abstract: The thermal properties of V2O5 and W0.04V2O5 pellets with α-V2O5 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-V2O5 thin films. In thermal diffusivity measurement, neither pellet showed a remarkable change in terms of strong electron-phonon interaction. The thermal diffusivity of the V2O5 pellet was about 20% larger than that of the W0.04V2O5 pellet due to the increase of surface defects of the nanospheres and the boundaries between them. The thermal conductivities of the V2O5 and W0.04V2O5 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 V2O5 pellet was larger than that of W0.04V2O5, 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 V2O5 and W0.04V2O5 pellets, and the transition temperatures (Tc) of the pellets were 200 and 180°C, respectively.
Keywords: V2O5; W0.04V2O5; pellet; thermal conductivity; MIT; metal-insulator transition; specific heats; thermal diffusivity.
International Journal of Nanotechnology, 2019 Vol.16 No.4/5, pp.228 - 236
Published online: 03 Jan 2020 *Full-text access for editors Access for subscribers Purchase this article Comment on this article