86424 20260128112903.0 doi 10.1016/j.jeurceramsoc.2018.12.049 sideral 109572 ART-2019-109572 eng Torres, M.A. Universidad de Zaragoza (orcid)0000-0003-3995-5763 Significant enhancement of the thermoelectric performance in Ca3Co4O9 thermoelectric materials through combined strontium substitution and hot-pressing process 2019 Access copy available to the general public Unrestricted This work explores the possibilities for a further enhancement of the thermoelectric properties of Ca3Co4O9 by Sr-doping combined with hot-pressing. Modified hot-pressing process resulted in highly-textured and dense ceramics. Sr-doping significantly improves electrical properties, resulting in extremely large power factor (1.2 mW/K2m at 800 °C) due to simultaneous electrical resistivity decrease and Seebeck coefficient increase. The main effect on cumulative electrical performance is provided by the Seebeck coefficient, reaching 270µV/K at 800 °C. XPS revealed relatively high average cobalt oxidation state at room temperature (+3.3), compared to materials produced by conventional sintering. The results of combined XPS and Auger electron spectroscopy emphasize the importance of high densification in Ca3Co4O9-based ceramics for preventing phase decomposition and interaction with CO2 and moisture. Still, despite the exceptional electrical performance, the calculated figure-of-merit (estimated as 0.29 at 800 °C) is around the best reported in the literature due to a high thermal conductivity (4.4 W/K m at room temperature). info:eu-repo/grantAgreement/ES/DGA/T54-17R info:eu-repo/grantAgreement/ES/MINECO-FEDER/MAT2017-82183-C3-1-R info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es 4.495 2019 MATERIALS SCIENCE, CERAMICS 1 / 28 = 0.036 2019 Q1 T1 1.164 2019 Materials Chemistry 2019 Q1 Ceramics and Composites 2019 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Costa, F.M. Flahaut, D. Touati, K. Rasekh, S. (orcid)0000-0003-3466-9952 Ferreira, N.M. Allouche, J. Depriester, M. Madre, M.A. Universidad de Zaragoza (orcid)0000-0002-0794-3998 Kovalevsky, A.V. Diez, J.C. Universidad de Zaragoza (orcid)0000-0001-9995-6368 Sotelo, A. Universidad de Zaragoza (orcid)0000-0001-7056-0546 5002 305 Universidad de Zaragoza Dpto. Ingeniería Diseño Fabri. Área Expresión Gráfica en Ing. 5001 065 Universidad de Zaragoza Dpto. Ciencia Tecnol.Mater.Fl. Área Cienc.Mater. Ingen.Metal. 39, 4 (2019), 1186-1192 J. Eur. Ceram. Soc. Journal of the European Ceramic Society 0955-2219 848906 http://zaguan.unizar.es/record/86424/files/texto_completo.pdf Postprint 1341796 http://zaguan.unizar.es/record/86424/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:86424 articulos driver 2026-01-28-11:25:00 ARTICLE