Electrical conductivity and oxygen stoichiometry of SrFeO3-delta

Solid-electrolyte coulometry, thermogravimetry, and conductivity (sigma) data obtained at temperatures from 20 to 1000 degrees C and oxygen partial pressures from 1 to 10(5) Pa were used to construct the equilibrium p-T-x and p-T-sigma phase diagrams of strontium ferrate, SrFeO3-delta. Strontium ferrate was shown to be p-type throughout the temperature and p(O2) ranges studied. Cooling polycrystalline SrFeO3-delta in flowing oxygen or air was found to be accompanied by sharp changes in resistivity.