Investigation of the conductivity of the lithium borosilicate glass system

The lithium borosilicate system (Li2O)(0.4)(B2O)((0.6x))(Si2-O4)(0.6(1-x)) with x = 0, 0.2, 0.3, 0.4, 0.6, and 0.8 was investigated using impedance spectroscopy. Impedance spectra were taken in the frequency range from 50 Hz to 1 MHz and in the temperature range from 100 to 280 degrees C. The ac- and dc-concluctivity, relaxation frequency and activation energy of the dc-conductivity were extracted from the impedance spectra. The dc-conductivity of the investigated glass samples increases almost linearly from silica rich (x = 0) to the boron rich (x = 0.8) samples. Activation energy (E-a) was found to be 0.65 eV for high conducting sample and 0.8 eV for low conducting sample, respectively. The mixed glass-former effect was not observed on the samples studied. The effect of temperature scaling of ac-conductivity was observed, which indicates, that ionic conductivity relaxation mechanism is temperature independent for samples with x = 0, 0.2, 0.3. However, some deviations from scaling were found for the samples with higher x (x = 0.4, 0.6, 0.8). (c) 2007 Elsevier B.V. All rights reserved.