ELECTRICAL RELAXATION IN A CDF2-LIF-ALF3-PBF2 GLASS AND MELT

Electrical impedance measurements as a function of frequency were carried out on a CdF2-LiF-AlF3-PbF2 (CLAP) glass both below and above the glass transition temperature. Data were analyzed in the electric modulus formalism, and the Kohlrausch-Williams-Watts beta parameter characterizing the width of the distribution of electric field relaxation times determined. beta was temperature-independent for the glass below the glass transition temperature, T-g, but decreased with increasing temperature for the melt above T-g. A similar temperature dependence of beta above T-g has been observed for fused nitrate, alkali silicate, alkali borosilicate and lead berate melts and for extremely concentrated electrolyte solutions, suggesting that this is a general phenomenon for ionically conducting liquids with large concentrations of mobile ions.