TALITA GISHITOMI FUJIMOTO
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Artigo IPEN-doc 28528 Electrical conductivity of La0.9Sr0.1Ga0.8Mg0.2O3-y-La1.55Sr0.45Ga3O7+δ composite electrolyte2021 - FUJIMOTO, T.G.; STEIL, M.C.; MUCCILLO, E.N.S.Doped lanthanum gallate constitutes a family of solid electrolytes with high ionic conductivity, wide electrolytic domain, and good chemical stability. The combination of its properties turns some compounds of this family promising candidates for application in solid oxide cells operating at intermediate temperatures. In this work, La0.9Sr0.1Ga0.8Mg0.2O3-y - xLa1.55Sr0.45Ga3O7+δ with x = 0, 1, and 5 wt.% were investigated aiming to obtain a composite solid electrolyte with optimized properties compared to the parent material. Composite electrolytes were prepared by solid state reaction method and evaluated for densification, phase content, and microstructure. Electrical conductivity measurements were carried out as a function of temperature and oxygen partial pressure. Increase on densification and structural homogeneity were obtained with increasing fraction of the melilite phase. The electrical conductivity determined by impedance spectroscopy revealed a decrease of the bulk resistivity for increasing amounts of La1.55Sr0.45Ga3O7+δ.Resumo IPEN-doc 25984 Preparation and characterization of solid electrolyte compounds consisting of doped lanthanum gallate and yttria stabilized zirconia2019 - FUJIMOTO, T.; MUCCILLO, E.Resumo IPEN-doc 25481 Ionic conductivity of Sr- and Mg-doped lanthanum gallate with La1.55Sr0.55Ga3O7+delta addition2018 - FUJIMOTO, T.G.; MUCCILLO, E.N.S.; CARVALHO, L.A.Sr- and Mg-doped lanthanum gallates are solid electrolytes with ionic conductivity higher than that of the traditional yttria-stabilized zirconia. Moreover, doped lanthanum gallates exhibit wide electrolytic domain and good chemical stability. The combination of their properties turns this compound a promising candidate for application in solid oxide fuel cells operating at intermediate temperatures (550-750°C). In this work, small amounts of La1.55Sr0.55Ga3O7+δ was added to doped lanthanum gallate and the effects of the additive on electrical properties of the base material were investigated by the impedance spectroscopy technique. The X-ray diffraction patterns of sintered specimens show the characteristic reflections of the perovskite-type phase, along with low-intensity diffraction peaks of the commonly detected impurity phases. The impedance spectroscopy diagrams reveal the high-frequency arc due to the bulk resistivity besides a strong overlap of the grain boundary arc with that of the electrode. The grain resistivity decreases for increasing amounts of La1.55Sr0.55Ga3O7+δ.