Abstract
Recently mixed conducting K 2 NiF 4 -type materials containing interstitial oxygen, such as La 2 Ni 1-x Co x O 4+ ∂ have been attracting attention as potential solid oxide fuel cell cathode materials. In this paper, we report a detailed structural investigation of the related system, La 2-x Sr x CoO 4+ ∂ (0 ≤ x S 1), to examine how the structure and the interstitial oxygen content varies with Sr content. The results show that for 0.2 ≤ x ≤1, the system adopts a tetragonal 14/mmm cell, while for x ≤ 0.1, the structure becomes orthorhombic, space group Abma. For samples containing high Sr contents (x > 0.5), there is no evidence for any interstitial oxygen, and consequently the Co oxidation state decreases from 3+ to 2.6+ in this range. For lower Sr contents, the level of interstitial oxygen increases with decreasing Sr content, such that the Co oxidation remains approximately constant (≃2.6+) in the range, 0 S x ≤ 0.5. The structural results are discussed in comparison to literature conductivity data.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.