Nucleation and Crystal-growth In A 0.9li2o.0.1bao.2sio2 Glass - A Dta Study

The devitrification behaviour of a 0.9Li2O· 0.1BaO· 2SiO2 glass has been studied by differential thermal analysis in order to evaluate the effect of substitution of a small amount of BaO for Li2O on the nucleation and the growth kinetics of lithium disilicate crystals. The value of the activation energy for crystal growth is very close to that for crystal growth in a lithium disilicate glass. A method for evaluating the effect of heat treatments in the nucleation temperature range on bulk crystallization kinetics is also proposed. The results suggest that the bulk nucleation rate of lithium disilicate crystals is lowered remarkably by the presence of BaO