Varistors
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Grain-Boundary Resistance and Nonlinear Coefficient Correlation for SnO2-Based Varistors
This work has focused on the electrical and microstructural properties of Nb2O5-doped SnO2-MnO2 ceramics. The pellets were prepared by solid-state reaction method according to the system (99.5-x) SnO2 - 0.5 MnO2 - x Nb2O5, on the following molar ratio x = 0.05; 0.10; 0.15; 0.20 and 0.25. Scanning electron microscopy and electrical measurements (ac and dc) we
Mat. Res.. Publicado em: 26/09/2016
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2. Study of substitution of Nb2O5 by Sb2O3 and the effect of calcination on the microstructure and electrical properties of SnO2 - based Varistors. / ESTUDO DA SUBSTITUIÇÃO DE Nb2O5 POR Sb2O3 E EFEITO DA CALCINAÇÃO SOBRE A MICROESTRUTURA E PROPRIEDADES ELÉTRICAS DE VARISTORES DE SnO2
Neste trabalho estudou-se sistematicamente a substituição do Nb2O5 por Sb2O3 na composição de um sistema varistor ternário e estudo da calcinação de sistemas binários e multicomponentes e sua relação microestruturapropriedade elétricas. Na Parte I do trabalho, estudo da substituição do Nb2O5 por Sb2O3, as composições foram preparadas via proce
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 19/12/2011
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3. Microstructural and nonohmic properties of ZnO.Pr6O11 CoO polycrystalline system
The microstructure and electrical properties of varistors composed of (95-x) ZnO + x Pr6O11 + 5 CoO (ZPC), (x = 0.1, 0.5 and 1.0) and sintered at 1300 and 1350 °C, were investigated. According to X-ray diffraction, several phases (ZnO, Pr2O3 and Pr2CoO4) are present when x = 1.0. Using Scanning Electron Microscopy, all of these compositions contain precipit
Materials Research. Publicado em: 2010-03
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4. Revisão - efeito dos metais doadores nas propriedades elétricas e microestruturais dos varistores cerâmicos à base de SnO2 = Review - effect of donor metals on the electrical and microstructural properties of SnO2-based ceramic varistors / Review - effect of donor metals on the electrical and microstructural properties of SnO2-based ceramic varistors
O estudo da adição de dopantes trivalentes é uma das principais pesquisas na área de varistores. Vários autores têm buscado entender os efeitos destes dopantes nas propriedades elétricas e microestruturais destas cerâmicas eletrônicas. Tanto metais de transição quanto terras raras são adicionados em cerâmicas à base de SnO2 a fim de verificar o
Publicado em: 2010
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5. Desenvolvimento de varistores à base de SnO2 para aplicação em redes de alta tensão = Development of SnO2-based varistors for high voltage application / Development of SnO2-based varistors for high voltage application
Varistores à base de SnO2 foram preparados pelo processo convencional de mistura de óxidos. As amostras foram sinterizadas a 1250 °C por 2 h. Os difratogramas obtidos por difração de raios X e as análises por microscopia eletrônica de varredura mostraram a presença de uma única fase. Altos valores de coeficientes de não-linearidade foram obtidos pa
Publicado em: 2010
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6. Influence of drying on the characteristics of zinc oxide nanoparticles
The recent growth in the field of porous and nanometric materials prepared by non-conventional processes has stimulated the search of new applications of ZnO nanoparticulate. Zinc oxide is an interesting semiconductor material due to its application on solar cells, gas sensors, ceramics, catalysts, cosmetics and varistors. In this work, the precipitation met
Brazilian Journal of Physics. Publicado em: 2009-04
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7. ESTUDO DA CINÉTICA DE SINTERIZAÇÃO DO SISTEMA SnO2.ZnO
The polycrystalline ceramics study the base of SnO2 presents great interest due to the inherent properties of emiconductor, which allows the application in some types of components, such as, protective gas sensors, varistors, protects films for different refractory uses and for glasses fusion of heavy metals. The addition of ZnO to the SnO2, makes with that
Publicado em: 2007
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8. Microstructural evaluation of rare-earth-zinc oxide-based varistor ceramics
Zinc oxide varistors are nonlinear voltage dependent ceramic resistors used to suppress and limit transient voltage surges. The work reported in this paper involves the relationship between microstructural characteristics and the varistor performance of ZnO ceramics doped with rare-earth oxides. Samples of these ceramics with different nonlinear current-volt
Materials Research. Publicado em: 2005-12
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9. AVALIAÇÃO METROLÓGICA DE VARISTORES DE ÓXIDO DE ZINCO PARA MÉDIA TENSÃO / METROLOGICAL EVALUATION OF ZINC OXIDE VARISTORS OF MEDIUM VOLTAGE
Despite its many benefits, one of the few disadvantages of semiconductor technology is the vulnerability of solid state devices to undesired increase in temperature, voltage and current . Even low voltage pulses can produce interference and damages with several consequences. Thus, as electronics are used in more and more applications, temperature, protection
Publicado em: 2004
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10. Caracterização de sistemas varistores a base de SnO2-MnO2. / Characterization of varistors systems SnO2-MnO2 based.
This work focussed on the effect of addition of Nb2O5 on the electrical and microestructural properties of SnO2-MnO2 based ceramics. It was also studied the effect of heat-treatments in a oxygen-rich atmosphere in these properties. The parent system was 99,5% SnO2-0,5% MnO2 in molar ratio, a dense system that did not present non-ohmic behavior. The addition
Publicado em: 2002