REMARKABLE NON-EXPONENTIALITY OF THE ENTHALPY RELAXATION IN FAST-ION CONDUCTING GLASS (AGI)(0.5)(AGPO3)(0.5) FAR FROM EQUILIBRIUM

The heat capacities of AgI-based fast ion conducting glass (AgI)(0.5)(AgPO3)(0.5) precooled at different rates mere precisely measured by using an adiabatic calorimeter in the temperature range of 290-373 K. The glass transition was observed at around 350 K. The fictive temperature in the configurational degree of freedom of the 'drop-smash' quenched sample was assessed to be 362 K which is about 11 K higher than that of the 'ordinarily' quenched sample. The spontaneous enthalpy-evolution processes of the glasses precooled at different rates were analyzed in terms of the equation of Kohlrausch, Williams and Watts, The estimated fractional exponent, beta, was 0.20 for the 'drop-smash' quenched sample showing significant deviation of the enthalpy relaxation from exponential behavior, and the beta was observed to become larger with decrease in the deviation of the glass from the equilibrium state.