Conductivity of doped LaGaO3 prepared by citrate sol-gel method

Abstract

Lanthanum-gallate powders (LSGM), with composition La1-xSrxGa1-yMgyO3-δ (0 ≤ x, y ≤ 0.2), were prepared using citrate solgel method. As-synthesized powders were calcined at 900°C, uniaxially pressed and sintered in air at different temperatures (up to 1450°C). Sintered samples contained cubic perovskite phase, while only pure LaGaO3 had small amount of the secondary orthorhombic phase. Sintering temperature of 1450°C with dwell time of 2 hours was sufficient to obtain samples with densities higher than 95% TD, with exception of pure LaGaO3. Impedance spectroscopy measurements confirmed that obtained LSGM ceramics have total conductivity an order of magnitude higher than zirconiabased electrolyte. Thus, citrate sol-gel method used in this work is a promising synthesis route for production of the doped lanthanum-gallate for intermediate temperature solid oxide fuel cells