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Navegando IF - Trabalhos de Conclusão de Curso por Assunto "Barium titanate"

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    Estudo das propriedades estruturais, morfológicas e elétricas de cerâmicas de Titanato de Bário (BaTiO3) otimizadas com Óxido de Zinco (ZnO)
    (Universidade Federal de Goiás, 2024-02-02) Alves, Luiz Henrique Borges; Silva, Hermínia Veridiana dos Santos Pessoni e; Silva, Hermínia Veridiana dos Santos Pessoni e; Alves, Thiago Eduardo Pereira; Franco Júnior, Adolfo
    In this work, two sets of ceramic samples of Barium Titanate were produced and studied, one produced from commercially available powder and the other from the precursors Barium Carbonate (BaCO3) and Titanium Dioxide (TiO2) through Solid State Reaction. Zinc Oxide (ZnO) was added as a sintering additive to obtain ceramic pellets, with a sintering temperature (1200 °C) lower than usual (≥ 1350 °C). The samples were studied using the Archimedes method, X-ray Diffraction, Rietveld Refinement, Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy and Dielectric Permittivity Spectroscopy. The determination of density using the Archimedes method demonstrated a relationship between the increase in densification of the pellets with the increase in the concentration of ZnO, observing an increase of at least 6% in densification with the addition of ZnO. X-ray Diffraction allowed the verification of the formation of the BaTiO3 phase for all samples without the formation of spurious phases, as well as obtaining the lattice parameters for the samples through Rietveld refinement. Fourier Transform Infrared Spectroscopy allowed us to observe how the addition of ZnO impacts the characteristic bands of the T i − O bond, with a slight shift of the band bottom to regions of lower wave numbers as the concentration of the additive increases. Scanning Electron Microscopy made it possible to observe the reduction in porosity in the samples as the additive concentration was increased, as well as the comparison of grain sizes between samples. Dielectric Permittivity Spectroscopy made it possible to observe the dielectric permittivity of the samples, with values of the order of εr = 10³ being observed in a wide frequency range for the sample with more optimized electrical properties with the addition of additive. With these results, the obtaining of Barium Titanate ceramics with structural, morphological and electrical properties of interest was optimized among the different routes studied.