Electrical conductivity of fluorite phases in the system Y_(2)O_(3)-Ta_(2)O_(5)-MgO

摘要

Electrical conductivity of fluorite phases in the system Y_(2)O_(3)-Ta_(2)O_(5)-MgO has been studied. Y_(0.8)Ta_(0.2)O_(1.7) fluorite phase, having 15 mol% oxygen ion vacancies, showed the maximum electrical conductivity. Electrical conductivity of Y_(0.8)Ta_(0.2)O_(1.7) fluorite phase increased linearly with P_(H_(2)O)~(1/2) due to the contribution of protonic conduction in water vapour. The electrical conductivity of the fluorite phase increased more remarkably at lower temperature, 700℃, than at higher temperatures, 800℃ and 900℃. The obtained results imply that the protonic conduction greatly contributes to the electrical conductivity of the fluorite phases in the system Y_(2)O_(3)-Ta_(2)O_(5)-MgO in water vapour.