resumo
Layered-type ordering and oxygen vacancies ordering are revealed in GdBaMnFeO6-delta perovskite. Selected area electron diffraction and high-resolution transmission electron microscopy results indicate a modulation of the crystal structure. Ba and Gd ordering in (001)(p) layers is confirmed by high angle annular dark field scanning transmission electron microscopy and electron energy-loss spectroscopy. These techniques also revealed formation of layer-stacking defects in the crystals. Direct imaging of the oxygen sublattice is obtained by phase image reconstruction. Location of the oxygen vacancies in the (GdO)(x) layers is achieved by analysis of the intensity of the averaged phase image. Physical properties of the GdBaMnFeO6-delta perovskite, are likely to be strongly affected by its ordering effects and crystal microstructure. In this sense, layered-type GdBaMnFeO6-delta perovskite show better electrochemical properties as cathodes in SOFCs than ion disordered Gd0.5Ba0.5Mn0.5Fe0.5O3-delta perovskite.
palavras-chave
OXIDE FUEL-CELLS; FAST OXYGEN DIFFUSION; CATHODES; PRBACO2O5+DELTA
categoria
Chemistry
autores
Munoz-Gil, D; Avila-Brande, D; Urones-Garrote, E; Garcia-Martin, S
nossos autores
Daniel Muñoz Gil
Bolseiro de pós-Doutoramentoagradecimentos
Authors thank the Spanish MINECO for funding projects MAT2013-46452-C4-4-R, PIB2010JP-00181 and CAM for project MATERYENER3CM-S2013/MIT-2753. We thank the ICTS-Centro Nacional de Microscopia Electronica of U.C.M. for technical assistance.