LAUSR

Abstract Differential thermal analysis (DTA) patterns of SiO 2 -Al 2 O 3 -CaO-CaF 2 oxy-fluoride glass system with adding different amounts of Y 2 O 3 from 0.5 (wt%) to 1.5 (wt%) have been studied under isochronal circumstances. It is concluded that, the crystallization of the glasses is a process controlled by Avrami nucleation, three dimensional diffusion controlled growth and anisotropic growth impingement mode. Afterwards, the effective activation energy Q p , growth exponent, nucleation activation energy Q N , and growth activation energy Q G , have been determined and were in the range of 283–321 kJ mol −1 , 2.05–2.25, 190–249 kJ mol −1 and 325–349 kJ mol −1 , respectively. Q p , Q N , Q G and n p are increased with increase of Y 2 O 3 amount, which is related to the network forming role of Y 2 O 3 in these systems.