Structural, magnetic and catalytic properties of a new vacancy ordered perovskite type barium cobaltate BaCoO2.67

Research output: Contribution to journalArticlepeer-review


  • Aamir Iqbal Waidha
  • Humera Khatoon Siddiqi
  • Yuji Ikeda
  • Maren Lepple
  • Sami Vasala
  • Manuel Donzelli
  • A D Fortes
  • Blazej Grabowski
  • Ulrike I Kramm
  • Oliver Clemens

Colleges, School and Institutes

External organisations

  • Institute for Problems of Materials Science National Academy of Sciences in Ukraine
  • Technische Universitat Darmstadt
  • College of Material Science and Engineering, Beijing Institute of Fashion Technology
  • DECHEMA Forschungsinstitut
  • ISIS Pulsed Neutron and Muon Source
  • University Stuttgart


A new vacancy ordered, anion deficient perovskite modification with composition of BaCoO2.67(Ba3Co3O8􀀀1) has been prepared via a two-step heating process. Combined Rietveld analysis of neutron and X-ray powder diffraction data shows a novel ordering of oxygen vacancies not known before for barium cobaltates. A combination of neutron powder diffraction, magnetic measurements, and density functional theory (DFT) studies confirms G-type antiferromagnetic ordering. From impedance measurements, the electronic conductivity of the order of 10-4 S cm-1 is determined. Remarkably, the bifunctional catalytic activity for oxygen evolution reaction (OER)and oxygen reduction reaction (ORR) is found to be comparable to that of Ba0.5Sr0.5Co0.8Fe0.2O3–y, confirming that charge-ordered anion deficient non-cubic perovskites can be highly efficient catalysts.


Original languageEnglish
JournalChemistry: A European Journal
Early online date28 Apr 2021
Publication statusE-pub ahead of print - 28 Apr 2021


  • Perovskite, Neutron diffraction, ab initio calculations, magnetism, bifunctional catalyst