Propriedades multifuncionais de solução sólida de CeO2 substituída com lantânio
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Data
2017-02-17
Autores
Deus, Regina Celia de [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Filmes espessos de CeO2 puro e dopado com La foram obtidos pelo processo de Tape Casting e suas propriedades dielétricas, não ôhmicas e resistivas avaliadas. Dentre as composições estudadas, o sistema com 8 mol% em La mostrou-se mais eficaz em reduzir a corrente de fuga com histerese mais simétrica. Para este estudo, as nanoparticulas utilizadas para a produção da barbotina foram sintetizadas pelo método HAM, a 100°C por 8 minutos, utilizando o mineralizador KOH. A barbotina foi feita em solvente aquoso, necessitando de ótimo controle das condições do ambiente para que a fita produzida tenha condição de ser estudada. Por outro lado, não há toxicidade e inflamabilidade no filme confeccionado por esse solvente, sendo agradável para o ambiente. As propriedades estruturais, opticas e elétricas dos filmes obtidos pelo processo de Tape Casting foram estudadas pelos métodos de caracterização de difração de raios X, microscopia eletrônica de varredura, medidas de área especifica de superfície, espectroscopia eletrônica na região do ultravioleta-visível e por medidas tensão-corrente, variando-se o campo elétrico e a frequência. A partir dos resultados obtidos pelos experimentos de laboratório, tendo como base a literatura, foi possível revelar e compreender algumas características do CeO2 puro e dopado com La.
Undoped and lanthanum doped CeO2 were obtained by the Tape Casting process and the dielectric, non-ohmic and resistive memories were evaluated. From all investigated systems, the one which reduces the leakage current with symmetric hystereses was the 8 mol% in La. For this study, the nanoparticles used for the production of the slip were synthesized by the HAM at 100°C for 8 minutes, using KOH mineralizer. The suspension was made in an aqueous solvent, requiring optimal control of environmental conditions that produced the tape has condition to be studied. Moreover, no toxicity and flammability in the film made by this solvent being pleasant to the environment. The structural, optical and electrical of the films obtained by the tape casting process were studied by the methods of characterization of X-ray diffraction, scanning electron microscopy, area measurements specific surface, electronic spectroscopy in the ultraviolet-visible region and measures voltage-current by varying the electric field and frequency. From the results obtained by laboratory experiments, based on the literature, it was possible to reveal and understand some CeO2 features pure and doped with La.
Undoped and lanthanum doped CeO2 were obtained by the Tape Casting process and the dielectric, non-ohmic and resistive memories were evaluated. From all investigated systems, the one which reduces the leakage current with symmetric hystereses was the 8 mol% in La. For this study, the nanoparticles used for the production of the slip were synthesized by the HAM at 100°C for 8 minutes, using KOH mineralizer. The suspension was made in an aqueous solvent, requiring optimal control of environmental conditions that produced the tape has condition to be studied. Moreover, no toxicity and flammability in the film made by this solvent being pleasant to the environment. The structural, optical and electrical of the films obtained by the tape casting process were studied by the methods of characterization of X-ray diffraction, scanning electron microscopy, area measurements specific surface, electronic spectroscopy in the ultraviolet-visible region and measures voltage-current by varying the electric field and frequency. From the results obtained by laboratory experiments, based on the literature, it was possible to reveal and understand some CeO2 features pure and doped with La.
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Palavras-chave
CeO2, Hidrotermal micro-ondas, Nanoestruturas, Hydrothermal Microwave, Nanostructures