Redox transitions in strontium vanadates: Electrical conductivity and dimensional changes

摘要: Abstract The reversibility of redox-induced phase transformations and accompanying electrical conductivity dimensional changes in perovskite-type SrVO 3− δ , a parent material for family potential solid oxide fuel cell anode materials, were evaluated employing X-ray diffraction, thermal analysis, dilatometry measurements. At 873–1273 K, the is metallic-like 6–8 orders magnitude higher compared to semiconducting V 5+ -based strontium pyrovanadate Sr 2 O 7 orthovanadate 3 8 existing under oxidizing conditions. easily oxidized at atmospheric oxygen pressure. Inverse reduction 10%H –90%N atmosphere occurs two steps through (5Sr  + SrV 6 11 ) intermediate. As relatively stable even reducing conditions, perovskite its high level cannot be recovered completely reasonable time span temperatures ⩽1273 K. Dilatometric studies confirmed that  ↔ Sr redox transformation accompanied with significant changes. Their extent depends on degree conversion and, apparently, microstructural features.