Synthesis and characterizations of A-site deficient perovskite Sr0.9Ti0.8−xGaxNb0.2O3

The effects of reduction and Ga-doping on the physicochemical properties of A-site deficient perovskites Sr0.9Ti0.8−xGaxNb0.2O3 (x = 0, 0.05, 0.1, 0.15 and 0.2) are reported. With 10% Ga doping, the sample sintered in air and treated at 1400 °C in H2 atmosphere exhibits the highest electrical conductivity. It is found that the Ga-doping lowers the sinterability but promotes the reduction of Sr0.9Ti0.8−xGaxNb0.2O3. The XRD analysis on the reduced samples suggests that some cations are reduced during the treatment. However, without high temperature pre-reduction, the improvement of Ga-doping is limited and the overall cell performance using Sr0.9Ti0.8−xGaxNb0.2O3 as an anode without catalysts is still relatively low.