Abstract: The nucleation and crystallization behavior of Li₂O-Al₂O₃-SiO₂ glasses with varied amounts of Fluorine content were investigated by the differential thermal analysis (DTA), X-ray diffraction (XRD) and
the scanning electron microscopy (SEM). The results show that with the increase of the fluorine concentration, the crystallization peak temperature
(T_p) decreases, the crystallization activation energy (E) decreases, the Avrami exponent (n) increases. The onset of the
precipitation of Li_xAl_xSi_1-xO₂ crystal and its transformation to β-spodumene all shift to lower temperature and the grain size increases with the fluorine added. The values
of the Avrami exponent (n) and the crystallization activation energy (E) agree well with the scanning electron microscopy observation of
equivalent axis grain crystal. The results suggest that the fluorine promotes the initial crystallization and ion diffusion in the glass system.

Key words: differential thermal analysis, glass-ceramics, nucleation, crystallization