Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T22:25:53Z No. of bitstreams: 1 CarolineGomesMoura_DISSERT.pdf: 2102873 bytes, checksum: c954d6aaea1a58ccd102a726f8bae793 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-01T23:05:31Z (GMT) No. of bitstreams: 1 CarolineGomesMoura_DISSERT.pdf: 2102873 bytes, checksum: c954d6aaea1a58ccd102a726f8bae793 (MD5) / Made available in DSpace on 2016-04-01T23:05:31Z (GMT). No. of bitstreams: 1 CarolineGomesMoura_DISSERT.pdf: 2102873 bytes, checksum: c954d6aaea1a58ccd102a726f8bae793 (MD5) Previous issue date: 2015-06-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / O PSFC (Pr0.5Sr0.5Fe1-xCuxO3-?) ? um novo ?xido misto com estrutura perovskita que vem sendo estudado para aplica??o como catodo de c?lulas a combust?vel de ?xido s?lido de temperatura intermedi?ria (600-750 ?C), principalmente devido a sua elevada condutividade i?nica e eletr?nica abaixo de 800 ?C. Neste trabalho, p?s de PSFC com duas composi??es diferentes (Pr0,5Sr0,5Fe0,8Cu0,2O3-PSFC5582 e Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) foram sintetizados pelo m?todo dos citratos utilizando uma nova rota. Os p?s obtidos foram caracterizados por an?lise t?rmica (Termogravimetria e Calorimetria Diferencial Explorat?ria), e os materiais calcinados a 800, 900 e 1000 ?C por 5h foram analisados por difratometria de raios X (DRX), com refinamento Rietveld dos dados de difra??o e dilatometria. Filmes de composi??o PSFC5582 foram obtidos por serigrafia do p? calcinado a 1000 ?C. Os filmes foram depositados em substrato de c?ria dopada com gadol?nia (CGO) e sinterizados a 1050 ?C por 2h. O desempenho eletroqu?mico dos eletrodos foi avaliado por espectroscopia de imped?ncia e a interface eletrodo/eletr?lito foi observada por microscopia eletr?nica de varredura (MEV). A resist?ncia espec?fica por ?rea (ASR) foi 0,44 ?.cm? a 800 ?C, um valor pouco inferior aos reportados na literatura para catodos contendo cobalto. Os coeficientes de expans?o t?rmica (CET) do PSFC de ambas as composi??es variaram entre 13 e 15 x 10-6 ?C-1 , numa faixa de temperatura de 200 a 650 ?C, demonstrando a boa compatibilidade t?rmica destes catodos com eletr?litos de Ce0,9Gd0,1O1,95 (CET = 12 x 10-6 ?C). / The PSFC (Pr0.5Sr0.5Fe1-xCuxO3-?) is a new mixed oxide perovskite and has been studied and evaluated the cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs), mainly due to its good compatibility with the electrolyte (CGO) and its high ionic conductivity and electronic in intermediate temperature. In this work, PSFC powders with two different compositions (Pr0,5Sr0,5Fe0,8Cu0,2O3- PSFC5582 and Pr0,5Sr0,5Fe0,6Cu0,4O3-PSFC5564) were synthesized by the citrate method using a new route. The powders obtained were characterized by thermal analysis (Differential Scanning Calorimetry and Thermogravimetry), and the material calcined at 800, 900 and 1000 ?C for 5h were analyzed by X-ray diffractometry (XRD), with the Rietveld refinement of the diffraction data and dilatometry. PSFC5582 composite films were obtained by screen printing of powder calcined at 1000 ?C. The films were deposited on substrate ceria doped with gadolinia (CGO) and then sintered at 1050 ?C for 2h. The electrochemical performance of the electrodes was evaluated by impedance spectroscopy and the interface electrode/electrolyte was observed by scanning electron microscopy (SEM). The specific resistance area (ASR) was 0.44 ?.cm? at 800 ?C, slightly lower than those reported in the literature for cathodes containing cobalt. The thermal expansion coefficients of both the PSFC compositions were obtained and varied between 13 and 15 x 10-6 ?C-1 , in a temperature range of 200 to 650 ?C, demonstrating the good thermal compatibility of cathodes with Ce0,9Gd0,1O1,95 electrolytes (CET = 12 x 10-6 ?C).