Studies on structural, morphological and electrical properties of Ce1−xErxO2−δ (x = 0.05–0.20) as solid electrolyte for IT – SOFC

• Published in: Materials chemistry and physics 2015-03, Vol.153, p.422-431
• Main Authors: Stojmenović, M., Bošković, S., Žunić, M., Babić, B., Matović, B., Bajuk-Bogdanović, D., Mentus, S.
• Format: Article
• Language: English
• Subjects: Ceramics; Electron microscopy (TEM and SEM); Oxides; Raman spectroscopy; Sintering; X-ray scattering
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2015.01.036

A series of four different powders ceria doped Ce1−xErxO2−δ (0.05 ≤ x ≤ 0.20) were synthesized by applying self-propagating reaction at room temperature (SPRT method). SPRT procedure is based on the self-propagating room temperature reaction between metal nitrates and sodium hydroxide, wherein the reaction is spontaneous and terminates extremely fast. The method is known to assure very precise stoichiometry of the final product in comparison with a tailored composition. XRPD, Raman spectroscopy, TEM and BET measurements were used to characterize the nanopowders at room temperature. It was shown that all obtained powders were single phase solid solutions with a fluorite-type crystal structure and all powder particles have nanometric size (about 3–4 nm). Densification was performed at 1550 °C, in an air atmosphere for 2 h. XRPD, SEM and complex impedance method measurements were carried out on sintered samples. Single – phase form was evidenced for each sintered materials. The best value of conductivity at 700 °C amounted to 1.10 × 10−2 Ω−1 cm−1 for Ce0.85Er0.15O2−δ sample. Corresponding activation energies of conductivity amounted to 0.28 eV in the temperature range 500–700 °C. •Ce1−xErxO2−δ (0.05 ≤ x ≤ 0.20) powders were synthesized using self-propagating reaction.•Obtained powders were single-phase solid solutions with a fluorite-type crystal structure.•Grain size distribution of sintered samples was in the range of 1–2 μm.•The highest conductivity was 1.10 × 10−2 Ω−1 cm−1 at 700 °C for Ce0.85Er0.15O2−δ sample.•Activation energies of samples were around 0.28 eV in the range 500–700°.