Microstructural evaluation of rare-earth-zinc oxide-based varistor ceramics
Título del documento: Microstructural evaluation of rare-earth-zinc oxide-based varistor ceramics
Revista: Materials research
Base de datos: PERIÓDICA
Número de sistema: 000312860
ISSN: 1516-1439
Autors: 1



2
Institucions: 1Centro de Pesquisa de Energia Eletrica, Rio de Janeiro. Brasil
2Universidade Federal do Rio de Janeiro, Departamento de Engenharia Metalurgica e de Materiais, Rio de Janeiro. Brasil
Any:
Període: Oct-Dic
Volum: 8
Número: 4
Paginació: 425-429
País: Brasil
Idioma: Inglés
Tipo de documento: Nota breve o noticia
Enfoque: Experimental
Resumen en inglés 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-voltage characteristics, according to the specific chemical composition and sintering parameters, were prepared and microstructurally analyzed by scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray fluorescence spectroscopy and X-ray diffraction. The results denote that intergranular phase is rich in rare-earth elements, but its morphology, obtained by selective leaching of ZnO grains (which are only doped with Co), provides evidence that ZnO grains are not completely surrounding by the intergranular phase, also existing ZnO grains are in direct contact with each other, as well as it occurs in conventional varistor system
Disciplines Ingeniería
Paraules clau: Ingeniería de materiales,
Ingeniería eléctrica,
Cerámica,
Oxido de zinc,
Microestructuras,
Varistores,
Propiedades eléctricas
Keyword: Engineering,
Electrical engineering,
Materials engineering,
Ceramics,
Zinc oxide,
Microstructures,
Varistors,
Electrical properties
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