Ionic and electronic conductivity in CaTi0.9Fe0.1O3-delta

The electrical conductivity of CaTi1-xFexO3-delta (x = 0.1) was measured by an alternating current van der Pauw technique versus oxygen partial pressu re (10(-30)-1 atm) and temperature (450-1200 degrees C). The results were i nterpreted to reflect n-type, ionic and p-type conductivity at respectively low, intermediate and high oxygen partial pressures. The apparent activati on enthalpy for the ionic conductivity, interpreted to reflect the mobility of oxygen vacancies, was 0.87 eV. The enthalpy of intrinsic formation of e lectronic defects (apparent band gap E-g) was 3 eV. The results are compare d with literature data for CaTi0.8Fe0.2O3-delta and with Fe-substituted SrT iO3 and discussed in terms of iron-oxygen vacancy association and ordering.