Influence of fluorine content on the crystallization behavior of apatite-wollastonite glass-ceramics

The influence of substituting fluorine for oxygen in the apatite-wollastonite (AW) glass composition on the crystallization behavior was analyzed followed by differential thermal analysis and X-ray diffraction. It was shown that Apatite crystallizes at a lower temperature than Woillastonite, as it favors bulk nucleation and the latter surface nucleation. It was found that increasing the fluorine content disrupts the glass network, replacing bridging oxygens with non-bridging fluorines and results in a reduction in transition temperature (Tg) and both crystallization temperatures.