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).