Oxygen content and thermodynamic stability of YBaCo4O7±δ

YBaCo4O7±δ was found to be thermodynamically stable in air at T>900°C whereas its thermodynamic stability at 950°C is limited by the range of oxygen partial pressures −5.05≤log(pO2/atm)≤−0.5. Oxygen content in YBaCo4O7±δ at 950°C slightly decreases from 7.009 at log(pO2/atm)=−0.5 to 6.953 in the atmosphere with log(pO2/atm)=−5.05. YBaCo4O7±δ decomposes into the mixture of YCoO3–δ, BaCoO3–δ and Co3O4 at 950°C in atmosphere with log(pO2/atm)>−0.5 whereas in atmosphere with log(pO2/atm)900°C.•Thermodynamic stability at 950°C is limited by the range of −5.05≤log(pO2/atm)≤−0.5.•Oxygen content in YBaCo4O7±δ at 950°C slightly decreases from 7.009 to 6.953.