Jump to main content
Jump to site search

Issue 6, 2018
Previous Article Next Article

The p(O2)–T stability domain of cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ

Author affiliations


Cubic perovskite-type Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) is one of the mixed ionic-electronic conductors with the highest oxygen permeability known to date. It serves as a parent material for the development of functional derivatives for electrochemical applications including oxygen separation membranes, solid electrolyte cell electrodes and electrocatalysts for the oxygen evolution reaction. The present study is focused on the determination of the precise stability boundaries of cubic perovskite BSCF employing a coulometric titration technique in combination with thermogravimetric analysis, X-ray and neutron diffraction, and molecular dynamics simulations. Both the low-p(O2) and high-p(O2) stability boundaries at 700–950 °C were found to correspond to a fixed value of oxygen content in the perovskite lattice of 3 − δ = ∼2.13 and ∼2.515, respectively. The stability limits in this temperature range are expressed by the following equations: high-p(O2) boundary: log p(O2) (atm) (±0.1) = −10 150/T (K) + 8.055; low-p(O2) boundary: log p(O2) (atm) (±0.03) = −20 750/T (K) + 4.681. The p(O2)–T phase diagram of the BSCF system under oxidizing conditions is addressed in a wider temperature range and is shown to include a region of precipitation of a “low-temperature” phase occurring at 400–500 °C. The fraction of the low-temperature precipitate, which co-exists with the cubic perovskite phase and is stable up to 790–820 °C, increases upon increasing p(O2) in the range 0.21–1.0 atm.

Graphical abstract: The p(O2)–T stability domain of cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Oct 2017, accepted on 11 Jan 2018 and first published on 11 Jan 2018

Article type: Paper
DOI: 10.1039/C7CP07307K
Citation: Phys. Chem. Chem. Phys., 2018,20, 4442-4454
  •   Request permissions

    The p(O2)–T stability domain of cubic perovskite Ba0.5Sr0.5Co0.8Fe0.2O3−δ

    A. A. Yaremchenko, M. V. Patrakeev, E. N. Naumovich and D. D. Khalyavin, Phys. Chem. Chem. Phys., 2018, 20, 4442
    DOI: 10.1039/C7CP07307K

Search articles by author