Atomic Structure Analysis of a Second Order Ruddlesden-Popper Ferrite-a High Resolution STEM Study

Judith Lammer, Christian Berger, Daniel Knez, Pauolo Longo, Gerald Kothleitner, Nina Schrödl, Edith Bucher, Andreas Egger, Rotraut Merkle, Werner Sitte, Joachim Maier

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review


New energy materials based on mixed proton-, oxygen ion- and electron-conducting ceramics (triple conducting oxides, TCOs) offer attractive possibilities for future applications in protonic ceramic fuel cells, electrolyser cells or membranes for hydrogen separation. Fundamental research is of high interest when it comes to mass and charge transport as well as defect chemistry – properties of new TCOs, which are influenced by the crystal structure. In this work, we show an elemental analysis at atomic resolution of the second order Ruddlesden-Popper ferrite Ba1.1La1.9Fe2O7. We characterized the atomic structure by X-ray diffraction and high-resolution scanning transmission electron microscopy. Furthermore, we revealed the position of the elements in the crystal structure via high-resolution elemental maps using electron energy loss spectrometry and energy-dispersive X-ray spectrometry. This enables us to distinguish between La and Ba, both located at the A-sites within the A3B2O7 phase: Our experiments show that La favours the 9-fold coordination sites in the rock salt layer, whereas Ba prefers the 12-fold coordination sites within the perovskite block. Comparing the intensities of atom columns on one specific site, we recognized slight fluctuations in Ba and La concentrations, which point to cation diffusion within the crystallites. These new insights on cation ordering in Ba1.1La1.9Fe2O7 may further contribute to the understanding of mass and charge transfer properties
Original languageEnglish
Title of host publicationEuropean Materials Research Society
PagesZ 1.7
Publication statusPublished - 2019
EventEuropean Materials Research Society Spring Meeting 2019: EMRS 2019 - Nizza, Nice, France
Duration: 27 May 201931 May 2019


ConferenceEuropean Materials Research Society Spring Meeting 2019
Abbreviated titleE-MRS 2019
Internet address

ASJC Scopus subject areas

  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Basic - Fundamental (Grundlagenforschung)

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