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Memorias de investigación
Artículos en revistas:
The influence of area/volume ratio on microstructure and non-Ohmic properties of SnO2-based varistor ceramic blocks
Áreas de investigación
  • Cerámicos,
  • Fisica so -- materia condensada blanda,
  • Materiales magnéticos
Times Cited: 2 References: 23 Citation Map Abstract: This work deals with the electrical properties of SnO2-based varistor systems with different area-volume (A/V) ratio of the green compact. The influence of A/V ratio specially on microstructural homogeneity and different diameter-thickness (D/t) ratio of sintered compact mainly as a requisite to the existence of non-Ohmic properties is evaluated. The results evidence that, contrary of what is generally observed for ZnO-based varistor system, in the SnO2-based system, the A/V ratio of the green compacts does not influence the non-Ohmic properties, i.e. the homogeneity of the microstructure and the composition after sintering is conserved independently of the A/V ratio employed in the green compacts. Such independence was specifically observed by performing non-Ohmic measurement after cutting the sintered blocks in different slices and observing that the current-voltage curve of the slices are very similar for different A/V ratio of the green compacts before sintering. The observed behavior has its origin on the fact that A/V ratio does not affect the microstructure development during sintering due to the minimal CoO losses by vaporization for SnO2-based system, i.e. the stability of the dopant oxides is high when compared with that used in commercial ZnO center dot A Bi2O3-based varistors in which, for instance, Bi2O3 volatilizes critically. On the other hand, it was found a critical value of A/V = 5.0 cm(-1) for the ceramic blocks to effectively served as varistor, below this ratio the ceramics were highly resistive because of a high number of effective barriers 85% which is higher than normally found for ZnO-based systems (35%).
Título de la revista
Journal of materials science. Materials in electronics
Factor de impacto JCR
Información de impacto
Número de revista
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Esta actividad pertenece a memorias de investigación
  • AUTOR: ELSON LONGO (Sao Paulo State Univ, Inst Quim)
  • AUTOR: MIGUEL A. RAMIREZ (Sao Paulo State Univ, Inst Quim)
  • Autor: Jose Francisco Fernández Lozano (UPM)
  • Autor: Jose de Frutos Vaquerizo (UPM)
  • AUTOR: PAOLO BUENO (Sao Paulo State Univ, Inst Quim)
  • Autor: Miguel Ángel De La Rubia López (UPM)
  • AUTOR: JOSE ARANA VARELA (Sao Paulo State Univ, Inst Quim)
Grupos de investigación, Departamentos, Centros e Institutos de I+D+i relacionados
  • Creador: Grupo de Investigación: Propiedades ópticas, eléctricas y magnéticas de materiales y sus aplicaciones (POEMMA)
  • Departamento: Física Aplicada a las Tecnologías de la Información
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