abstract
Composite materials based on gadolinium doped ceria (CGO) with additions of silica, with both silica and lanthanum oxide, and with lanthanum silicate, were prepared by the conventional ceramic route, to assess the silica scavenging role of lanthanum oxide additions. Structural, microstructural and electrical characterization of these samples confirmed the formation of one apatite type lanthanum silicate-based phase from reaction of silica with lanthanum oxide. The formation of this phase occurred in parallel with a significant enhancement of the grain boundary conductivity of these composite materials. Further interaction between constituents, involving diffusion of La to CGO, and Cc and Gd to the apatite phase, had no significant consequences on the electrical performance of these materials. Overall, lanthanum oxide was shown to remove the siliceous phases from the grain boundaries of CGO.
keywords
IONIC-CONDUCTIVITY; ALUMINA ADDITION; ZIRCONIA; CERAMICS; TRANSPORT; OXIDE; DY
subject category
Materials Science
authors
Ivanova, D; Kovalevsky, A; Kharton, VV; Marques, FMB
our authors
Andrei Kavaleuski
Principal Researcher
Fernando Manuel Bico Marques
Full professor
Vladislav Kharton
Invited Principal Researcheracknowledgements
D. Ivanova grant was Supported by the Erasmus Mundus Joint Masters Programme (CEC-Brussels). Financial Support from FCT (Portugal) is greatly appreciated.