Surface and volume crystallization in fluorrichterite based glasses

Abstract

F-richterite based glasses in the SiO2-CaO-MgO-Na2O-F system were investigated by X-ray diffraction, differential scanning calorimetry and field emission scanning electron microscopy to ascertain the influence of fluorine content on preferential crystallization mechanism and on the spatial position of crystals developed in the initial steps of glass devitrification. The results highlight that both surface and volume mechanisms occur in the crystallization of fluorrichterite glasses. However, these glasses preferentially devitrify by a surface crystallization mechanism, although an increase of fluorine content leads to a modification in the location of the first developed crystals.