A PHENOMENOLOGICAL STUDY OF THE STRUCTURAL RELAXATION OF AN INORGANICGLASS (LI(2)O2SIO(2))

The structural relaxation process of an inorganic glass (Li(2)O2SiO(2) ) has been studied by differential scanning calorimetry. The sample is subjected to different thermal ageing histories with isothermal stage s at an ageing temperature of T-g - 30 degrees C for different ageing times and at an ageing time of 16 h for different ageing temperatures. A four-parameter Tool-Narayanaswamy-Moynihan (TNM) model, is applied to simulate the normalized specific-heat curves measured. The ageing-t emperature and ageing-time dependence of the structural relaxation par ameters in the TNM model is obtained. (C) 1998 Elsevier Science S.A. A ll rights reserved.