resumo
New oxides of the (NdSr)(n+1)MO3n+1 (M = Co and Mn or Fe) series are reported. Compounds of composition NdSrCo0.75Fe0.25O4.(10), NdSrCo0.75Mn0.25O4.08 and Nd0.5Sr1.5Co0.75Mn0.25O3.86 are the n = 1 members of the Ruddlesden-Popper homologous series (K2NiF4 structural type) as determined by X-ray diffraction and different transmission electron microscopy techniques. Their crystal structure consists of connected (Co-Fe/Mn)O-6 octahedra blocks separated by (Nd/Sr) O rock-salt like layers along the c-axis. Interstitial oxygen atoms or anion vacancies are induced depending on composition. Oxides with interstitial oxygen show good performances as intermediate temperature solid oxide fuel cell (IT-SOFC) cathode. The areaspecific resistance values of electrodes made of these oxides at 973 K in air are 0.18 Omega cm(2) for NdSrCo0.75Fe0.25O4.(10) and NdSrCo0.75Mn0.25O4.08 (comparable to the one of the state-of-the-art materials proposed as cathodes in IT-SOFC), and 1.38 Omega cm(2) for Nd0.5Sr1.5Co0.75Mn0.25O3.86.
palavras-chave
OXIDE FUEL-CELLS; ELECTRICAL-CONDUCTIVITY; K2NIF4-TYPE STRUCTURE; THERMAL-EXPANSION; CATHODE MATERIALS; OXYGEN REDUCTION; IONIC TRANSPORT; MAGNETORESISTANCE
categoria
Chemistry
autores
Boulahya, K; Gil, DM; Hassan, M; Martin, SG; Amador, U
nossos autores
Daniel Muñoz Gil
Bolseiro de pós-Doutoramentoagradecimentos
We thank the Ministerio de Economia y Competitividad (MINECO) and Comunidad de Madrid for funding the projects MAT2013-46452-C4-1-R and MAT2013-46452-C4-4-R, and S2013/MIT-2753, respectively.