Electrical conductivity of pure and doped α-ferric oxides

Electrical conductivities of αFe2O3 containing 1 2, 2 3 and 3 8 mol% CdO were measured in the temperature range of 300 to 1300°C at Po2's of 10−9 to 10−1 atm Plots of log σ vs1T at constant Po2's were found to be linear with an inflection at temperatures around 500°C and higher Po2's than 1 × 10−4 atm. The activation energies obtained by the least-squares method were 1 34 eV for the intrinsic region and 0 51 eV for the extrinsic region on αFe2O3 doped with 38 mol% CdO The extrinsic conductivities disappeared at lower Po2's than 1 × 10-4atm, and the intrinsic conduction appeared on the specimens investigated The electrical conductivities decreased with increasing amount of CdO doping The predominant defects in this system are believed to be interstitial Fe2 for the intrinsic region and oxygen vacancies for the extrinsic region.