JOSE FERNANDO QUEIRUGA REY
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Capítulo IPEN-doc 16269 Primary particle size effect on ohase transition in Basub(2)Insub(2)Osub(5)2007 - REY, J.F.Q.; FERREIRA, F.F.; MUCCILLO, E.N.S.Capítulo IPEN-doc 16680 Phase transition in Basub(2)Insub(2)Osub(5) studied by in situ high temperature X-ray diffraction using synchrotron radiation2009 - REY, J.F.Q.; FERREIRA, F.F.; MUCCILLO, E.N.S.The order-disorder phase transition in Ba,In,Os high-temperature ionic conductor was systematically studied by in situ high-temperature X-ray diffraction using synchrotron radiation and electrical conductivity. Pure barium indate was prepared by solid state reactions at 1300°C. The room-temperature structural characterization showed a high degree of phase homogeneity in the prepared material. The reduction of the order-disorder phase transition temperature was verified by electrical conductivity and high-temperature X-ray diffraction. The observed features were explained based on Fourier-transform infrared spectroscopy results that revealed the presence of hydroxyl species in the crystal lattice. The increase of the intensity of few diffraction peaks near the phase transition temperature suggests the formation of a superstructure before the orthorhombic-to-tetragonal phase transition.Capítulo IPEN-doc 14483 Quantum size effect as evidence by small-angle x-ray scattering of Insub(2)Osub(3) nanoparticles2009 - SOUZA, E.C.C.; REY, J.F.Q.; MUCCILLO, E.N.S.Resumo IPEN-doc 16180 Effect of solvent on surface structure characteristics of chemically synthesized samaria-doped ceria nanoparticles2010 - SOUZA, E.C.C.; REY, J.F.Q.; MUCCILLO, E.N.S.Resumo IPEN-doc 10139 Sol gel synthesis of Ba2In2O52004 - REY, J.F.Q.; MUCCILLO, E.N.S.Sólidos iônicos condutores de íons oxigênio têm sido extensivamente estudados devido ao seu potencial de aplicação como sensores de oxigênio, membranas permeáveis ao oxigênio, bombas de oxigênio e como eletrólitos para células de combustíveis à eletrólito sólido óxido (SOFC). Neste trabalho de pesquisa foi sintetizado o composto Ba2In2O5 por sol-gel. Para este material os valores de condutividade iônica, em condições especificas, são similares àqueles apresentados pela zircônia dopada. Na caracterização do material foram realizadas medidas de análise térmica, difração de raios X e espectroscopia de absorção na região do infravermelho, microscopia eletrônica de transmissão e varredura. Os resultados obtidos mostram todas as etapas de formação da fase, com estrutura cristalina do tipo brownmilleritta, possibilitando a redução dos tempos e temperaturas de formação da fase, quando comparado aos materiais preparados pela técnica convencional de mistura de óxidos.Resumo IPEN-doc 08925 Lattice parameters in yttria-doped ceria solid electrolytes2001 - REY, J.F.Q.; MUCCILLO, E.N.S.Cefia-rare earth solid solutions are known as solid electrolytes with potential applications in oxygen sensors and solid oxide fuel cells. Trivalcnt rare carth ions cnter finto solid solution introducing a number of anion vacancies for charge compensation. These oxygcn vacancies are quite mobile at low temperatures giving rise to a comparativcly high ionic conduction. In this study ccria-x mol% yttria solid solutions were prepared with x ranging from O to 12 by solid state reactions. These solid solutions cxhibit a fluorite-type structure with composition dcpendent lattice parameters. The variation of thc lattice parameter was studicd and corrclated with existing empirical equations based on ion packing model. The effcct of an effective ionic radius of Y3+ in eightfold coordination is also discussed.Artigo IPEN-doc 09525 Caracterizacao eletrica e microestrutural do Basub(2)Insub(2)Osub(5)2003 - REY, J.F.Q.; MUCCILLO, E.N.S.Artigo IPEN-doc 08870 Parametros de rede em eletrolitos solidos de ceria dopada com itria2002 - REY, J.F.Q.; MUCCILLO, E.N.S.Dissertação IPEN-doc 07610 Parametros de rede e resistividade eletrica em solucoes solidas de ceria - itria2002 - REY, JOSE F.Q.Artigo IPEN-doc 11404 Synthesis of Insub(2)Osub(3) nanoparticles by thermal decomposition of a citrate gel precursor2005 - REY, J.F.Q.; PLIVELIC, T.S.; ROCHA, R.A.; TADOKORO, S.K.; TORRIANI, I.; MUCCILLO, E.N.S.