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Previous issue date: 2009-02-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The present work aims the preparation of filmes of strontium-doped lanthanum manganite (perovskita) yttria-stabilized zirconia (LSM-SDC) films deposited on substrate of YSZ by means of spin coating technique having as principal objective
their application to solid oxide fuel cells of intermediate temperature. La0,8Sr0,2MnO3 and Ce0,8Sm0,2O1,9 were obtained by modified Pechini method by use of gelatin
which act as polymerization agent. The powders obtained were characterized by Xray fluorescence, X ray diffraction, electronic scanning microscopy and the superficial area by BET method. The results obtained by X-ray fluorescence showed that the route adopted for obtention of powders was effective in the obtention of the compositions with close values to the stoichiometrics. Ethyl cellulose was used as pore-forming agent and mixed with the LSM-SDC powders in weight proportions of 1:24, 2:23 and 1:9. The films were sintered at 1150 ?C for 4 h and characterized by X-ray diffraction and scanning electron microscopy technique (SEM) and atomic force. The phases quantification of the precursory powders and of the obtained films was carried through Rietveld method. According with the analysis of SEM, as the content of ethyl cellulose was increased, the pore distribution in films become more uniform and the pore size reduced. The methodology used for the obtention of the films was very efficient, considering a material was obtained with characteristics that were proper to the application as electrolyte/cathode system to solid oxide fuel cells / O trabalho trata da prepara??o de filmes de manganita de lant?nio dopado com estr?ncio (perovskita) c?ria dopada com sam?rio (LSM-SDC) sobre substrato de zirc?nia estabilizada com ?tria (YSZ) pela t?cnica spin coating, para utiliza??o em c?lulas a combust?vel de ?xido s?lido de temperatura intermedi?ria. Neste trabalho, La0,8Sr0,2MnO3 e Ce0,8Sm0,2O1,9 foram obtidos pelo m?todo Pechini modificado pelo uso de gelatina que atua como agente polimerizante e quelante. Os p?s obtidos foram caracterizados por fluoresc?ncia de raios-X, difra??o de raios-X, microscopia
eletr?nica de varredura e determina??o da ?rea superficial pelo m?todo BET. Os resultados obtidos por fluoresc?ncia de raios-X mostraram que a rota adotada para obten??o dos p?s foi eficaz na obten??o da composi??o com valores pr?ximos ao
estequiom?trico. A etilcelulose foi usada como agente formador de poros e foi misturada ao p?s de LSM-SDC em propor??es m?ssicas de 1:24, 2:23 e 1:9. Os filmes foram tratados termicamente a 1150 ?C por quatro horas e caracterizados estruturalmente pela t?cnica de difra??o de raios X e morfologicamente pelas t?cnicas de microscopia eletr?nica de varredura e for?a at?mica. A quantifica??o das
fases dos p?s precursores e dos filmes obtidos foi realizada atrav?s do refinamento Rietveld. De acordo com a an?lise de MEV, quando a quantidade de etilcelulose foi aumentada, a distribui??o dos poros nos filmes tornou-se mais uniformes e o
tamanho de poros reduzidos. A metodologia empregada para a obten??o dos filmes mostrou-se satisfat?ria, considerando que foi obtido um material com caracter?sticas apropriadas para a aplica??o como sistema eletrodo/eletr?lito em c?lulas a
combust?vel de ?xido s?lido (SOFC)
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17611 |
| Date | 04 February 2009 |
| Creators | Ces?rio, Moises R?molos |
| Contributors | CPF:06117988320, http://lattes.cnpq.br/3318871716111536, Melo, Marcus Ant?nio de Freitas, CPF:04514998320, http://lattes.cnpq.br/5840621182000517, Pimentel, Patr?cia Mendon?a, CPF:77858239449, http://lattes.cnpq.br/9303372770390061, Noronha, F?bio Bellot, CPF:92714102700, http://lattes.cnpq.br/4325989861878031, Melo, Dulce Maria de Ara?jo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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