Details

Autor(en) / Beteiligte

• Tsipis, Ekaterina V.
• Patrakeev, Mikhail V.
• Anikina, Polina V.
• Naumovich, Eugene N.
• Kharton, Vladislav V.

Titel

Redox behavior and ionic conductivity of Al-doped Sr3LaFe3O10−δ

Ist Teil von

• Materials letters, 2020-04, Vol.265, p.127425, Article 127425

Ort / Verlag

Amsterdam: Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Equilibrium p(O2)-T-δ diagrams of layered Sr3LaFe3−xAlxO10−δ were studied.•Statistical thermodynamic model was proposed and validated.•Thermodynamic parameters governing oxygen intercalation were calculated.•Charge-carrier concentrations and partial conductivities were determined. Mixed ionic-electronic conductors derived from Ruddlesden-Popper type Sr3LaFe3O10−δ are promising materials for numerous energy- and environment-related applications, such as electrodes of fuel cells, batteries and capacitors. In this work, oxygen deficiency and electrical conductivity of Sr3LaFe3−xAlxO10−δ (x = 0.3–0.6) were studied at 973–1273 K in the oxygen partial pressure range from 10−24 to 0.8 atm. The p(O2)-T-δ diagrams determined by coulometric titration and thermogravimetry, were described by a statistical thermodynamic model taking into account the site-exclusion effects near oxygen vacancies, energetic non-equivalence of different crystallographic sites, and partial localization of electron holes in the vicinity of Al3+ cations. Doping with Al3+ was found to increase oxygen nonstoichiometry under oxidizing conditions and to decrease the electronic charge-carrier concentrations. Although the oxygen vacancy mobility tends to decrease on doping due to stable tetrahedral coordination of Al3+ cations, a moderate increase in the ionic conductivity with respect to parent Sr3LaFe3O10−δ is observed at x = 0.3 and temperatures below 1100 K.