DEVITRIFICATION STUDY OF A CADMIUM FLUOROCHLORIDE GLASS

Isothermal and non-isothermal kinetic parameters of devitrification on reheating for a glass with composition, in molar fractions, 0.33CdCl2 , 0.17CdF2, 0.34NaF, 0.13BaF2, 0.03KF, were determined using a differe ntial scanning calorimeter. These determinations led to an apparent ac tivation energy of crystallization approximately 20 kcal/mol and a val ue on the Avrami exponent n between 2.2 and 2.5, corresponding to a di ffusion controlled growth and indicating a good stability of that glas s to crystallization. The influence of the chemical processing in the glass preparation on these parameters was studied.