Thermodynamic data of Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} SOFC cathode material

Journal Article · Mon Sep 15 04:00:00 EDT 2014 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2014.06.002· OSTI ID:22420558

Botea-Petcu, A. ^[1]; Varazashvili, V.; Lejava, N.; Machaladze, T.; Khundadze, M. ^[2]; Maxim, F.; Teodorescu, F. ^[1]; Martynczuk, J. ^[3]; Yáng, Z.; Gauckler, L. J. ^[4]

---

1. Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, Bucharest (Romania)
2. Ivan Javakhishvili Tbilisi State University, R. Agladze Institute of Inorganic Chemistry and Electrochemistry, Tbilisi, Georgia (United States)
3. Electron Microscopy ETH Zurich, ETH Zurich, Zurich (Switzerland)
4. Nonmetallic Inorganic Materials, Department of Materials, ETH Zurich, Zurich (Switzerland)

Graphical abstract: Partial molar energy of oxygen dissolution (ΔG{sup −}{sub O{sub 2}}) and equilibrium partial pressure of oxygen (log⁡p{sub O{sub 2}}) of perovskite material with the composition Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} as a function of temperature. - Highlights: • We report relevant data for thermodynamic stability of Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} perovskite compound. • Temperature of structural transformations related to the charge compensation of the material system is evidenced. • The results are discussed based on the properties-defect structure relationship. - Abstract: The compound Ba{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3−δ} with perovskite structure has been studied focusing mainly on the thermodynamic stability in correlation to the change in the oxygen stoichiometry. The thermochemical behavior has been investigated from room temperature to 1300 K by thermal gravimetry and differential thermal analysis in air and by calorimetry in scanning mode in Argon. The temperature dependence of enthalpy (ΔH{sup T}{sub 298}) in the temperature range of 300–900 K was measured by drop calorimetry. Thermodynamic properties represented by the relative partial molar free energies, enthalpies and entropies of oxygen dissolution in the perovskite phase, as well as the equilibrium partial pressures of oxygen have been obtained in the temperature range of 823–1273 K using solid electrolyte electrochemical cells (EMF). The influence of the oxygen stoichiometry on the thermodynamic properties was examined using a coulometric titration technique coupled with EMF measurements. The results are discussed based on the strong correlation between the energetic parameters and the charge compensation of the material system.

• OSTI ID: 22420558
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Vol. 57; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
CALORIMETRY
COBALT COMPOUNDS
DIFFERENTIAL THERMAL ANALYSIS
ELECTROCHEMISTRY
ELECTROMOTIVE FORCE
ENTHALPY
ENTROPY
FERRITES
FREE ENERGY
GRAVIMETRY
PARTIAL PRESSURE
PHASE TRANSFORMATIONS
SOLID ELECTROLYTES
SOLID OXIDE FUEL CELLS
STRONTIUM COMPOUNDS
TEMPERATURE DEPENDENCE
THERMAL GRAVIMETRIC ANALYSIS