Fe doping effects on phase stability and conductivity of La0.75Sr0.25Ga0.8Mg0.2O3−δ

The effects of Fe doping on phase stability and electrical conductivity were investigated for the 25 mol% Sr and 20 mol% Mg-doped lanthanum gallates (LSGM-2520). While secondary phases, in addition to perovskite phase, were formed for an undoped LSGM-2520 in accordance with previous reports, a single phase perovskite phase was obtained by addition of a small amount (∼4 mol%) of Fe to LSGM-2520. The conductivity of 4 mol% Fe-doped LSGM-2520 was as high as 0.17 S cm−1 at 800 °C and it was confirmed to be ionic based on its dependency on oxygen partial pressures. Crystallographic analysis using neutron diffraction and electron diffraction determined the crystal structure and lattice parameters for 4 mol% Fe-doped LSGM-2520.