Indexed on: 01 Jan '77Published on: 01 Jan '77Published in: Journal of Applied Electrochemistry
In order to examine the conduction behaviour in the sintered oxides of MoO3-doped Bi2O3, the electrical conductivity in air and the EMF of oxygen gas concentration cell were measured with respect to the phase relation determined by X-ray diffraction.The tetragonal single phase oxide containing 22 mol% MoO3 was found to be a high oxide ion conductor, the conductivity of which was comparable to those of stabilized zirconias. The partial electronic conduction in this phase was negligibly small at relatively high oxygen pressure. The oxide ion conduction was considered to be attributable to an appreciable amount of oxygen vacancies present in the crystal. In the monoclinic compound 3Bi2O3·2MoO3, the oxide ion conduction was also observed. Although the conductivity of this phase was somewhat lower than that of the tetragonal phase, the activation energy for conduction (53·5 kJ mol−1) was much lower than the values for usual oxide ion conductors.