OXYGEN ION CONDUCTION IN FCC BI2O3 DOPED WITH ZRO2 AND Y2O3

Electrical conductivity was measured for fcc Bi//2O//3 solid solutions in Bi//2O//3-ZrO//3-ZrO//2-Y//2O//3 system, which were made by using Y//2O//3-doped Bi//2O//3 (BY) and Y//2O//3-doped ZrO//2 (ZY). In the system with Y concentration of 20 at%, the fcc phase was formed at 0-10 mol% ZY and the oxygen-ion conductivity decreased with an increase in ZY. In system with Y//2O//3 concentration of 10 mol%, metastable fcc phase was formed at 0-14 mol% ZY and the conductivity below 600 degree C increased with an increase in ZY in the fcc monophase region and decreased in two-phase (BY and ZY) region. There was a correlation between lattice constant and conductivity at low temperatures. Addition of ZrO//2 was found to have some contribution to stabilization of fcc Bi//2O//3 but to be not so effective as that of Y//2O//3.