Electrical conduction behavior of A-site deficient (Y, Fe) co-doped SrTiO3 mixed ionic–electronic conductor

•A single cubic phase perovskite (Y0.08Sr0.92)1−xTi0.6Fe0.4O3−δ (x=0, 0.03, 0.05) was fabricated at 1350 °C by the sol–gel method.•A-site deficiency improved the total electrical conductivity of (Y0.08Sr0.92)1−xTi0.6Fe0.4O3−δ (x=0, 0.03, 0.05).•A-site deficiency enhanced the densification process of Y, Fe co-doped SrTiO3 materials, which promoted the chemical and electrical stability.•The possible charge compensation mechanism was concerned.

Mixed ionic–electronic conductors with high electrical conductivity have an important effect on modern electrochemical devices. As a mixed ionic–electronic conductor, a single cubic phase perovskite (Y0.08Sr0.92)1−xTi0.6Fe0.4O3−δ (x=0, 0.03, 0.05) was fabricated at 1350 °C in air by the sol–gel method. The total electrical conductivity of SrTiO3-based materials can be significantly enhanced by deficiency of A-site and acceptor-doping on B-site. In the paper, a remarkable enhancement of total electrical conductivity and sinterability of A-site deficient (Y, Fe) co-doped SrTiO3 is reported. In addition, the possible charge compensation mechanism of A-site deficient Y, Fe co-doped SrTiO3 can be described as (Y0.08Sr0.92)1−xFe0.4Ti4+0.92(1−x)−0.4Ti3+0.08(1−x)O3−(δ+0.4/2) or (Y0.08Sr0.92)1−xFe0.4Ti4+0.92(1−x)−y1Ti3+0.08(1−x)−y2O3−(δ+y1/2) (y1+y2=0.4).