Dynamics of Li+ ions in strontium metaphosphate glasses

Dynamics of Li+ ions in strontium metaphosphate glasses has been studied in the frequency range of 10 Hz-2 MHz and in the temperature range of 273-573 K. The dc conductivity increases and the activation energy decreases with the replacement of strontium ions by lithium ions in the glass compositions. The ac electrical data have been studied using the modulus and conductivity formalisms. We have observed that the stretching exponent decreases and the frequency exponent increases with the replacement of strontium ions by lithium ions in these glasses. The variation of these parameters was explained in terms of ion-ion interaction. The mobile ion concentration remains nearly constant, which indicates that the mobility of the migrating ions increases when the alkaline earth ions are replaced by the alkali ions. (C) 2007 American Institute of Physics.