Development of a system for measuring the complex impedance of borosilicate glasses at high pressures and temperatures: Application to the study of Li- and Na-doped borosilicate glasses

An apparatus for measuring the complex impedance of samples with high impedances is described. Complex impedance spectra were collected from a range of borosilicate glasses of composition (B2O3)4(Li2O)(LiBr)x(NaBr)1−x at pressures and temperatures ranging from 1 to 5 GPa and 350 to 450 °C, respectively. These data were used to determine AC conductivities and activation energies in order to test the Modified Random Network model of glass structure. Our results are in line with the predictions of this theory.