Resumo

MENDEZ-MARTINEZ, Francisco et al. Zn_x-1Cu_xMn₂O₄ Spinels; Synthesis, Structural Characterization and Electrical Evaluation. J. Mex. Chem. Soc [online]. 2010, vol.54, n.1, pp.2-6. ISSN 1870-249X.

This work presents the structural characterization and electrical evaluation of Zn_x-1Cu_xMn₂O₄ spinels, which are materials presented as secondary phases into the varistor ceramic systems. Samples were analyzed by X-ray diffraction, solid-state nuclear magnetic resonance, infrared spectroscopy, scanning electron microscopy and impedance spectroscopy. Although, the addition of copper to the ZnMn₂O₄ spinel did not produce morphological changes, the structure and electrical behaviors changed considerably. Structurally, copper addition induced the formation of partial inverse spinels, and its addition increases significantly the electrical conductivity. Therefore, the formation of Zn_x-1Cu_xMn₂O₄ spinels, as secondary phases into the varistor materials, may compromise significantly the varistor efficiency.

Palavras-chave : Ceramic; Impedance Spectroscopy; spinel; Varistor; XRD.

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