Effect of oxide defect structure on the electrical properties of ZrO2

The defect structure of monoclinic ZrO 2 was studied by measuring the transfer numbers and electrical conductivity as functions of O 2 pressure and temperature. The data suggest a defect structure of doubly ionized oxygen vacancies at low pressures, i.e. <10 −19 atm, and singly ionized oxygen interstitials at pressures >10 −9 atm. Zirconia is primarily an ionic conductor below #700°C and an electronic conductor at 700° to 1000°C for 10 −22 ≤P o2 ≤1 atm.