Structure and electrical properties of oxygen-deficient strontium copper niobate

The transport properties of Sr5.66 Cu0.14Nb2.20 O11.30 double perovskite, which enters the homogeneity region of (Sr1-yCuy)6–2xNb2+2xO11+3x solid solution, are concerned. The total conductivity is differentiated into terms over wide ranges of temperatures and oxygen partial pressures \( p_{O_2 } \) in dry and humid atmospheres. When \( p_{O_2 } \) is low or high, a test sample has dominant electron transport of n- or p-type, respectively. In air (\( p_{O_2 } \)= 0.21 atm), the p-type electron conductivity term increases with temperature elevation. In a humid atmosphere (\( p_{H_2 O} \) = 0.02 atm), a sample is capable of a reversible incorporation of water occlusion from the gas phase; as a result, some proton conductivity term appears and ion transference numbers increase over a wide range of \( p_{O_2 } \) values.