Resumo

VERGARA ESTUPINAN, O. C  e  GOMEZ CUASPUD, J. A. Synthesis and Characterization of the La_0,95Sr_0,05CrO₃. Ciencia en Desarrollo [online]. 2015, vol.6, n.1, pp.119-125. ISSN 0121-7488.

This work investigated the synthesis and characterization of a perovskite material based on the La_0,95Sr_0,05CrO₃ system, by a wet chemical route that involves the combustion-polymerization method, using citric acid as complexing agent, in order to obtain intermediate coordination species, which evolve depending on the temperature until the desired consolidation crystalline phase is obtained. The metal-organic precursor characterization was performed by thermal analyses (TGA-DTA), in order to evaluate an ideal consolidation temperature of the searched crystalline phase. The analysis by the X-ray diffraction (XRD), the transmission electron microscopy (TEM), the X-ray fluorescence microprobe (EDX) and the surface area (BET), were performed over the calcined ceramic material and revealed the obtention of a nanostructured orthorhombic crystal structure with a Pnma (62) space group, and a 20 nm crystallite average size. The analysis derived from the transmission electron microscopy, revealed that the material is composed of aggregates of nanometric range with a series of textural and specific morphological properties for an eventual application at the catalytic level, which is correlated with the data derived from the measurement of the surface area obtained by the BET technique. Finally, the composition by X-ray fluorescence assessment revealed that stoichiometric control in composition is one of the key parameters in this synthesis process, which allows to validate the used method and enables to employ the obtained materials in potential technological applications.

Palavras-chave : Perovskite; Citrate Method; Nanostructured Materials.

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