Test of Anderson-Stuart model and the "universal" conductivity in rubidium and cesium silicate glasses
An analysis and brief discussion of experimental ionic conductivity sigma and activation energy E A in the binary rubidium and cesium silicate systems is presented, exemplified on 23 and 30 glasses respectively, in a wide composition range (5-45 Rb2O and Cs2O mole%). The Anderson and Stuart model has been considered to describe the variation of activation energy E A with alkali concentration in both alkali-silica systems. In this analysis were considered experimental parameters, like shear modulus G and relative dielectric permittivity epsilon. An "universal" finding is obtained using logsigma× E A/kB T in 51 of 53 glasses considering both alkali systems, where E A is the activation energy for conduction, kB is the Boltzmann constant and T is the absolute temperature. This strong correlation by more than 13 (Rb-based glasses) and 15 (Cs-based glasses) orders of magnitude means that sigma is governed mainly by E A. An explanation for this behavior links ionic conductivity and microscopic structure.
Main Authors: | , , |
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Format: | Digital revista |
Language: | English |
Published: |
Sociedade Brasileira de Física
2005
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Online Access: | http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332005000400007 |
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