S?ntese e caracteriza??o do zirconato de c?lcio (CaZrO3)

• Main Author: Silva, Tales Gomes da
• Other Authors: 16225422404
• Language: Portuguese
• Published: PROGRAMA DE P?S-GRADUA??O EM QU?MICA 2018
• Subjects: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA; Perovskita; S?ntese de combust?o; Caracteriza??o
• Online Access: https://repositorio.ufrn.br/jspui/handle/123456789/24971

Submitted by Automa??o e Estat?stica ([e-mail]) on 2018-04-02T12:29:11Z No. of bitstreams: 1 TalesGomesDaSilva_DISSERT.pdf: 2074042 bytes, checksum: 9ab46c684188848b7c872a1879d30e61 (MD5) === Approved for entry into archive by Arlan Eloi Leite Silva ([e-mail]) on 2018-04-04T12:34:21Z (GMT) No. of bitstreams: 1 TalesGomesDaSilva_DISSERT.pdf: 2074042 bytes, checksum: 9ab46c684188848b7c872a1879d30e61 (MD5) === Made available in DSpace on 2018-04-04T12:34:21Z (GMT). No. of bitstreams: 1 TalesGomesDaSilva_DISSERT.pdf: 2074042 bytes, checksum: 9ab46c684188848b7c872a1879d30e61 (MD5) Previous issue date: 2018-01-15 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) === Compostos perovskitas, como o Zirconato de C?lcio, apresentam f?rmula estrutural ABO3 e formam uma classe de materiais com propriedades ?pticas, magn?ticas e el?tricas bem definidas, que tem diversas aplica??es cient?ficas e tecnol?gicas. As perovskitas ser?o retratadas neste trabalho, por apresentarem estabilidade f?sicoqu?mica e propriedades espec?ficas bem definidas. Portanto, este trabalho tem como objetivo analisar a s?ntese da perovskitas pelo m?todo de combust?o, realizando as caracteriza??es das amostras por interm?dio de difra??o de raios X (DRX), refinamento de Rietveld, Microscopia Eletr?nica de Varredura (MEV), Espectroscopia de Energia Dispersiva (EDX ou EDS) e Fluoresc?ncia de Raios-X. A evolu??o do processo de cristaliza??o do CaZrO3 e a composi??o das amostras foram acompanhadas por difra??o de raios X. Os padr?es de raios X obtidos foram refinados com o m?todo Rietveld. Para identificar a presen?a de defeitos e morfologia das amostras foram utilizadas microscopias eletr?nicas de varredura. Os m?todos de caracteriza??o mostraram diferen?as estruturais nas amostras em fun??o da varia??o da composi??o do sistema. Os resultados indicam uma transi??o de defeitos profundos para defeitos rasos, devido a presen?a de fases secund?rias no sistema. === Perovskite compounds, such as Calcium Zirconate, have ABO3 structural formula and form a class of materials with well-defined optical, magnetic and electrical properties, which has several scientific and technological applications. The perovskites will be portrayed in this work, because they present physicochemical stability and well defined specific properties. Therefore, this work aims to analyze the synthesis of perovskites by the combustion method, performing the characterization of the samples by means of X-ray diffraction (XRD), Rietveld refinement, Scanning Electron Microscopy (SEM), Dispersive Energy Spectroscopy EDX or EDS) and X-ray Fluorescence. The evolution of the CaZrO3 crystallization process and the composition of the samples were accompanied by X-ray diffraction. The obtained X-ray patterns were refined with the Rietveld method. Scanning electron microscopes were used to identify the presence of defects and morphology of the samples. The characterization methods showed structural differences in the samples in function of the variation of the composition of the system. The results indicate a transition from deep defects to shallow defects due to the presence of secondary phases in the system.