Oxygen content and thermodynamic stability of YBaCo4O7 ± δ

D.S. Tsvetkov (1) , Valérie Pralong (2) , N.S. Tsvetkova (1) , A.Y. Zuev (1)

1 UrFU - Ural Federal University [Ekaterinburg]
2 CRISMAT - Laboratoire de cristallographie et sciences des matériaux

Abstract 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) < - 5.05 Y2BaCoO5, BaCoO2 and CoO were identified as the products of YBaCo4O7 ± δ decomposition. © 2015 Elsevier B.V.

Keywords: 114; Oxygen content; Thermodynamic stability; YBaCo<inf>4</inf>O<inf>7</inf>

Domains: Chemical Sciences; Chemical Sciences; Cristallography; Chemical Sciences; Material chemistry; Chemical Sciences; Theoretical and/or physical chemistry

D.S. Tsvetkov, Valérie Pralong, N.S. Tsvetkova, A.Y. Zuev. Oxygen content and thermodynamic stability of YBaCo4O7 ± δ. Solid State Ionics, 2015, 278, pp.1-4. ⟨10.1016/j.ssi.2015.05.004⟩. ⟨hal-02184096⟩