| Summary: | Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) 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 (eloihistoriador@yahoo.com.br) 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.
|
|---|
