Evaluation of Nucleation Behavior of Li2O-SiO2 Glass by DTA
Takashi WAKASUGI, Takuya KADOGUCHI and Rikuo OTA
Abstract:Li2O-SiO2 glasses were heat-treated under various conditions for nucleation and were employed for DTA measurement to evaluate their nucleation behavior. Crystallization peak temperature, TC of 33Li2OĽ67SiO2 and 30Li2OĽ70SiO2 glasses showed a minimum at 460 and it is found that TC is a good measure for the number density of nuclei. On the other hand, TC of 40Li2OĽ60SiO2 and 36Li2OĽ64SiO2 glasses did not show a minimum because the growth rate of crystal during the heat-treatment was so large at temperatures above 460 that TC tended to decrease. In order to evaluate the nucleation behavior quantitatively from TC, the relationship between TC and the number density of nuclei in 33Li2OĽ67SiO2 glass which had been heat-treated for various lengths of time at different temperatures was obtained. A single correlation curve was obtained between TC and the number density of nuclei. Using this relationship, variation of the number density of nuclei for 33Li2O-67SiO2 glass with heat-treatment time at a given temperature (460oC) can be evaluated. Key Words:Nucleation, Number density of nuclei, Crystallization, DTA, Li2O-SiO2