The dielectric response of (GeO2)(x)(SiO2)(1-x) glasses prepared from aerogels by means of a new sol-gel recipe has been studied by impedance spectroscopy. Ac conductivity measurements on silica glasses doped with GeO2 in the range 10(-3) -1 mol% have been carried out over six decades, in the range 0.1 Hz-100 kHz, for temperatures between 300 and 783 K. At sufficiently high temperatures, a dc conductivity plateau has been observed in the frequency range investigated. For the compositions considered in the present study, the dc conductivity and the corresponding activation energy seem to be only slightly influenced by the doping with GeO2. Sodium ion impurities, detected in these glasses in a concentration of several tens of ppm, are most likely responsible for the dc conduction process. Furthermore, the mean activation energy happens to increase as the temperature is decreased, suggesting a temperature dependence of the number of mobile defects.

GeO2-doped silica glasses: an ac conductivity study

CUTRONI, Maria;MANDANICI, Andrea
2002-01-01

Abstract

The dielectric response of (GeO2)(x)(SiO2)(1-x) glasses prepared from aerogels by means of a new sol-gel recipe has been studied by impedance spectroscopy. Ac conductivity measurements on silica glasses doped with GeO2 in the range 10(-3) -1 mol% have been carried out over six decades, in the range 0.1 Hz-100 kHz, for temperatures between 300 and 783 K. At sufficiently high temperatures, a dc conductivity plateau has been observed in the frequency range investigated. For the compositions considered in the present study, the dc conductivity and the corresponding activation energy seem to be only slightly influenced by the doping with GeO2. Sodium ion impurities, detected in these glasses in a concentration of several tens of ppm, are most likely responsible for the dc conduction process. Furthermore, the mean activation energy happens to increase as the temperature is decreased, suggesting a temperature dependence of the number of mobile defects.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11570/1907685
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 13
  • ???jsp.display-item.citation.isi??? 13
social impact