Comparison of activation energies for the electrical conductivity of silicate glasses obtained by dc and ac techniques

Autor(es)

Ziemath, E. C. ; Escanhoela, Jr., C. A. ; Braunger, M. L.

• Tipo de documento: Artigo Científico
• Fonte: Solid State Ionics; v. 301, p. 146-151, MAR 2017.
• Citações Web of Science: 0

Resumo

The electrical conductivity of glasses with composition (mol%) 22Na(2)O center dot 8CaO center dot 65SiO(2)center dot 5MO(2) (M = Si, Ti, Ge, Zr, Sn, Ce) was evaluated by two different experimental methods: low-voltage ac impedance and high-voltage dc resistivity. The ac measurements were carried out by the traditional impedance spectroscopy between 90 and 415 degrees C. In the dc method, a steady-state electric field of about I MV/m was applied during 5 s at temperatures between 100 and 210 degrees C, and the onset current, I-0, was measured. Activation energies between 0.71 and 0.81 eV were obtained. The differences between the values obtained by the dc and the ac methods are within experimental errors. The high electric field does not influence the concentration nor the mobility of the charge carriers for these experimental conditions and glass compositions. The dc method applied showed to be a suitable alternative to determine the temperature dependence of the electric conductivity of glasses to further calculation of the activation energy. (C) 2017 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 08/07304-7 - Espectroscopia de Impedância em Vidros 22Na2O.8CaO.65SiO2.5MO2 (M = Si, Ti, Ge, Zr, Sn, Ce), sem e com Troca Iônica Ag+-Na+
• Beneficiário: Maria Luisa Braunger Fier
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 08/07238-4 - Condutividade elétrica e polarização térmica de vidros soda-cal-sílica contendo diferentes cátions tetravalentes
• Beneficiário: Carlos Augusto Escanhoela Júnior
• Modalidade de apoio: Bolsas no Brasil - Mestrado