TG-DTA study of mixed conductor Sr4(Fe1−xCox)6O13±δ in air and argon

The synthesis, structure, electrical conductivity and TG-DTA behavior in air and argon of the Sr4(Fe1−xCox)6O13±δ samples with x=0–0.417 were investigated. While the Sr4(Fe1−xCox)6O13±δ solid solutions being isostructural with Sr4Fe6O13 were formed for 0<x⩽0.25, the Sr4(Fe1−xCox)6O13±δ phase and the perovskite phase Sr(Fe1−yCoy)O3 coexisted for x=0.333 and the perovskite phases of Sr(Fe1−yCoy)O3 and SrCoO2.8 were formed along with a trace of CoO for x= 0.417. The total conductivity increased with increasing Co substitution and temperature. The relationship between the weight changes observed in TG experiments and the total conductivity is reported.