Electron/hole and ion transport in La1-xSrxFeO3 - δ

The conductivity of the entire solid solution La1-xSrxFeO3 - δ, where x=0.2, 0.4, 0.5, 0.7 and 0.9, in the oxygen partial pressure range 10-19-0.5 atm and temperatures between 750 deg. C and 950 deg. C is reported. The partial contributions from different charge carriers and the energetic parameters governing transport of charged species reveal that the lanthanum-strontium ferrites can be characterized as mixed, ion-electron conductors in the low oxygen pressure/high oxygen deficiency limit. The partial contributions to conductivity from oxygen ions, electrons and holes increase with strontium content and attain maximal values at x=0.5. Further increase in doping results in development of oxygen vacancy ordering phenomena and deterioration of conducting properties