Thermochemical expansion of mixed-conducting (Ba,Sr)Co0.8Fe0.2O3−δ ceramics

摘要: Abstract The thermal and chemical expansion of Ba 0.5 Sr Co 0.8 Fe 0.2 O 3− δ (BSCF) SrCo (SCF) mixed ionic-electronic conductors were studied in combination with oxygen nonstoichiometry ( ) at 298–1223 K p (O 2 ) = 10 −4 to 1.00 atm. In order minimize the effects phase separation or oxygen-vacancy ordering processes, data collected dynamic cooling mode using dense ceramic samples. procedure was justified by a very fast equilibration given high-temperature range demonstrated for ceramics samples different specific surface area. difference BSCF SCF temperatures ≥973 K found be ≤0.03 atoms per formula unit. demonstrates favorably smaller compared many other conductors, originating from variations larger unit cell less sensitive temperature changes. Excessive thermochemical impedes however use single-phase fuel cathodes planar mixed-conducting membranes.