Abstract
Ruddlesden-Popper type compounds have the general formula, An+1MnO3n+1±x (typically A is a rare earth, alkaline earth, M is a transition metal), and are constructed of perovskite-type layers separated by rock salt type blocks. While n = 1, 2 phases are typically straightforward to prepare, the synthesis of higher order (n > 2) systems is difficult. In this paper we show that chromate (CrO42−) doping can be exploited to stabilise new n = 3 Ruddlesden-Popper systems, Sr4Fe3-xCrxO10-δ: without chromate doping, a mixture of the n = 2 phase Sr3Fe2O7-x and perovskite-type SrFeO3-x is obtained. This can be explained by the stabilisation of the central perovskite building block by chromate incorporation, similar to prior work on sulfate and carbonate doping in this system. The structure, and Fe/Cr oxidation states were evaluated by X-ray diffraction, 57Fe Mössbauer spectroscopy and X-ray absorption spectroscopy supporting the incorporation of Cr as CrO42−. In order to examine the potential of these new systems for use as a SOFC cathode material, conductivity studies were carried out, which showed semiconducting behaviour with slightly higher conductivities than the sulfate doped counterparts.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
