Analysis of crystallization behavior in Li2O center dot 2SiO(2) glass by DTA method based on a liquid model

The crystallization behavior of Li2O . 2SiO(2) glass samples having different melting histories were analyzed by differential thermal analysis (DTA), The glass samples were prepared by remelting a quenched glass at 1300 degrees C or 1035 degrees C for 1 h, The glass melted at low temperature was found to crystallize earlier and to have lower crystallization peak temperature, T-C, than that melted at high temperature. The number density and sizes of crystals precipitated in glasses with the same heat treatment as the DTA run were measured and were found greater in number and larger in the glass melted at lower temperature compared with that at higher temperature, These results are in agreement with the liquid model that crystal embryos are preserved in melts even above liquids and their distribution depends on temperature.