Oxygen ion conduction in γ-Bi₂O₃ doped with Sb₂O₃

Abstract

Electrical conduction in bccγ-Bi₂O₃ doped with Sb₂O₃ was investigated by measuring electrical conductivity, as a function of temperature and oxygen partial pressure$P_{{\text{0}}_2 }$, and ionic transference number. Theγ-Bi₂O₃ doped with 1 to 3 mol% Sb₂O₃ was stable up to 550° C and showed an oxygen ionic conduction in the$P_{{\text{0}}_2 }$ region of 10⁵ to 10⁻⁹ Pa. As the Sb₂O₃ content increased, ionic conductivity increased up to 2.5 mol % Sb₂O₃ (1.8×10⁻³Ω⁻¹cm⁻¹ at 500° C) and then decreased. However, the activation energy for ionic conduction remained almost unchanged. It was proposed that theγ-Bi₂O₃ contains a lot of oxygen vacancies and incorporated Sb⁵⁺ ions at tetrahedral sites which affect the concentration of oxygen vacancy effective for conduction.