A Global Defect Chemistry Model for p-Type Mixed Ionic and Electronic Conductors

Abstract

A global defect chemistry model is presented to relate the properties of a variety of p type perovskite conductors, including chromites, manganites, and ferrites, which can be tailored as mixed ionic and electronic conductors (MIECs). It is found that oxygen nonstoichiometry in these p type MIECs can be correlated using reaction constant for oxygen vacancy generation. The values of reaction constant for oxygen vacancy formation can be obtained by simulating the electronic conductivity as a function of oxygen activity and temperature with the existing global model that is based on the concept of localized electron holes. The global defect chemistry model allows us to better understand and predict the electrochemical properties of perovskite type p-type conductors.