Ionic conductivity properties in bismuth germanate silicate glasses at various temperatures

Ionic conductivities in the bismuth germanate silicate (BGSO) glasses have been investigated in the frequency range 100 Hz to 15 MHz and in the temperature range from 300 K to above the glass transition temperature T-g. The frequency-dependent electrical data have been discussed in the framework of the complex impedance and the power-law conductivity. The electrical conductivity is strongly composition dependent and it follows the Arrhenius relation in the experimental temperature range. The activation energies of dc and ac conductivities obtained by the power-law analysis show that the BGSO glasses satisfy the Barton, Nakajima, and Namikawa (BNN) relation. The temperature-dependent interaction of conducting ions is discussed.