EFFECT OF OXYGEN PARTIAL-PRESSURE IN ATMOSPHERE ON THERMOELECTROMOTIVE FORCE OF SOLID ELECTROLYTES

A dependency of thermoelectromotive force of zirconia stabilized by 11 mol%CaO, 9 mol%MgO and 15mol%MgO on oxygen partial pressure in the atmosphere were observed. Oxygen partial pressure, temperature difference and temperature were controlled between 0.21 and 5 × 10-19 atm, between 50 and 400°C as well as between 700 and 1 250°C, respectively. Above about 5 × 10-5 atm of oxygen partial pressure the lower the oxygen partial pressure, the larger the thermoelectromotive force. Between about 5 × 10-5 and 5 × 10-15 atm, the lower the oxygen partial pressure, the larger the the thermoelectromotive force. Under about 5 × 10-15 atm, the lower the oxygen partial pressure, the larger the thermoelectromotive force. The phenomenon can be explained by an assumption that the observed thermoelectromotive force consisted by that induced by ions and electrons.