Sintering kinetics and oxide ion conduction in Sr-doped apatite-type lanthanum silicates, La9Sr1Si6O26.5

Autor: Bernard Soulestin, Alexandre Maitre, Sophie Beaudet-Savignat, Thierry Chartier, Anne-Laure Sauvet, Claire Bonhomme
Přispěvatelé: Science des Procédés Céramiques et de Traitements de Surface (SPCTS), Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM), Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), CEA Le Ripault (CEA Le Ripault), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Axe 1 : procédés céramiques, Université de Limoges (UNILIM)-Université de Limoges (UNILIM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Limoges (UNILIM)-Ecole Nationale Supérieure de Céramique Industrielle (ENSCI)-Institut des Procédés Appliqués aux Matériaux (IPAM)
Jazyk: angličtina
Rok vydání: 2009
Předmět:
Zdroj: Solid State Ionics
Solid State Ionics, 2009, 180, pp.1593-1598. ⟨10.1016/j.ssi.2009.10.009⟩
Solid State Ionics, Elsevier, 2009, 180, pp.1593-1598. ⟨10.1016/j.ssi.2009.10.009⟩
ISSN: 0167-2738
DOI: 10.1016/j.ssi.2009.10.009⟩
Popis: International audience; These last past years, a major interest has been devoted to decrease the working temperature of solid oxide fuel cells (SOFCs) down to about 700 °C. Apatite materials (La10−xSrxSi6O27−x/2) are attractive candidates for solid electrolytes, with a high ionic conductivity at these intermediate temperatures. An apatite powder (x=1) with a 0.75 μm mean particle size, produced by solid state reaction, was tape cast to obtain green sheets with a thickness of about 260 μm. On one hand, the densification mechanism of the apatite ceramic during the intermediate solid state sintering has been approached. It appeared from the kinetical tests performed under isothermal conditions between 1250 and 1550 °C, that densification could be controlled by the diffusion at grain boundaries of the rare-earth element, La, with an activation energy of 470 kJ/mol. On the other hand, conductivity measurements were performed on apatite samples sintered at 1400 and 1500 °C. The ionic conductivity was mainly sensitive to the presence of secondary phases at 1400 °C. The ionic conductivity of the apatite sintered at 1500 °C (mean grain size=3.9 μm) is equal to 1.2×10−2S/cm at 700 °C.
Databáze: OpenAIRE