Ionic conductivity and local structural features in Ce1−xSmxO2−x/2. Issue 44 (6th November 2018)

• Record Type: Journal Article
• Authors: Presto, S.; Artini, C.; Pani, M.; Carnasciali, M. M.; Massardo, S.; Viviani, M.
• Is Part Of: Physical chemistry chemical physics. Volume 20:Issue 44(2018)
• Page Start: 28338
• Page End: 28345
• Publication Date: 2018-11-06
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c8cp04186e
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Manuscript correlates microstructure and transport properties modification, which might suggest a way to prepare better performing SOFC electrolyte materials. Abstract : Sm-Doped ceria is one of the most promising materials to be used as electrolyte in solid oxide fuel cells due to its remarkable ionic conductivity values in the intermediate temperature range. Transport properties and local structural features of Ce1− x Sm x O2− x /2 (0.1 ≤ x ≤ 0.7) were studied by an impedance/μ-Raman spectroscopy coupled approach up to 1073 K. Results suggest that C-based nanosized defect clusters are responsible for the drop in ionic conductivity observed even at x = 0.2, i.e. at a Sm content lower than necessary to allow C domains to reach the percolation threshold through crystallites. Moreover, within the fluorite-type compositional region, with increasing the Sm content, defect clusters undergo a rearrangement resulting in the enlargement of C-based domains rather than in the increase of their number; at higher x, on the contrary, both the size and amount of C domains increase in parallel.