Partial electronic conductivity of Sr and Mg doped LaGaO3

The partial electronic conductivities (σel) of La0.9Sr0.1Ga0.9Mg0.1O2.90 (LSGM9191), La0.9Sr0.1Ga0.8Mg0.2O2.85 (LSGM9182) and La0.8Sr0.2Ga0.8Mg0.2O2.80 (LSGM8282) were measured by Hebb–Wagner ion-blocking method between 700 and 900 °C. As the Sr and Mg content increases, both the hole and the electron conductivity decrease together with the increasing activation energy of conduction. The electronic transference numbers of the three compositions were approximately 10−2∼10−3, much larger than that of zirconia. From the Hebb–Wagner curves, the variation of σel was obtained as a function of oxygen partial pressure (PO2). The thermal band-gap energy (Eg) value was estimated from the conductivity minima. The possible sources of error in estimating Eg were discussed. Eg value was much smaller than that of yttria-stabilized zirconia (YSZ).