Structural Characterisation of the Potential SOFC Cathode Materials, La2−xSrxCoO4+ ∂ (0 ≤ x ≤ 1.0)
Year: 2005
Type: article
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 ≤ 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 I4/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 ≤ x ≤ 0.5. The structural results are discussed in comparison to literature conductivity data.
Source: ECS Proceedings Volumes
Author: R. Heap
Institution: University of Surrey
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W653519945