Resumo

GIRALDO TOBON, Eugenio  e  ABAD MEJIA, Pablo. OBTAINING PRECURSORS WITH NANO AND MICROMETRIC PARTICLE SIZE FOR THE SYNTHESIS OF CERAMIC MATERIALS WITH NONLINEAR ELECTRICAL PROPERTIES. Rev.EIA.Esc.Ing.Antioq [online]. 2014, n.spe1, pp.15-23. ISSN 1794-1237.

Results are compared with respect to electrical performance of the sintered material from ceramics precursor powders with nonlinear electrical properties, known as varistors. The synthesis routes investigated to reduce the particle size to nanometer distributions are controlled precipitation, Pechini method and the traditional method of mixed oxides. The matrix of the powders is based on ZnO doped with Bi, Mn and Sb and monitoring is made on intermediate and final stages of the process by X-ray diffraction and scanning electron microscopy. We analyze the results of the sintering process established under temperature-time programs of the precursor material, based on Thermo gravimetric Analysis techniques and Differential Thermal Analysis. The results show the superiority of the chemical routes compared to the mixture of oxides since with the former it is possible to obtain smaller particle sizes, lower densification temperature, and improved electrical responses given by higher nonlinearity coefficients and lower leakage currents.

Palavras-chave : Varistor; Controlled Precipitation; ZnO; Chemical Route; Nanoparticles.

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