Resumo

SANTIAGO T., M.; HERNANDEZ-CRUZ, L. E.; MONTIEL, H.  e  FLORES-GONZALEZ, M. A.. Síntesis y estudio de resonancia paramagnética electrónica de CaMnO₃ y Eu_0.05Ca_0.95MnO₃ obtenidos por coprecipitación. Superf. vacío [online]. 2010, vol.23, n.4, pp.25-30. ISSN 1665-3521.

The synthesis and characterization of Eu_0.05Ca_0.95MnO₃, obtained by the chemical coprecipitation method are presented. In order to modify the morphology and particle size, the use of triocty1 phosphine oxide (TOPO) as surfactant was also studied. The resulting materials were characterized by X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electronic microscopy (SEM) and electron paramagnetic resonance (EPR). The samples were refined by Rietveld method on orthorhombic structure and pnma spatial group, resulting in a single phase with the proposed stoichiometry composition. Particles with acicular morphology and sub-micrometric size were obtained when TOPO was utilized. As for the EPR analysis of Eu_xCa_1-xMnO₃ showed mixed values states of Mn³⁺and Mn⁴⁺ cations, demonstrating that divalent alkaline cation substitution by rare earth ion was carried out.

Palavras-chave : Synthesis; Microstructure; Manganite; Coprecipitation; Electronic paramagnetic resonance.

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