The influence of NiO on phase separation and crystallization of glasses of the MgO–Al2O3–SiO2–TiO2 system

Abstract The evolution of structure and phase composition of NiO-doped titania-containing magnesium aluminosilicate glasses has been studied using small angle X-ray scattering and X-ray diffraction analysis. After initial heat-treatments, three-phase immiscibility develops resulting in precipitation of two amorphous phases. One of them is enriched in MgO, Al 2 O 3 and TiO 2 , the other in MgO and Al 2 O 3 . Nickel oxide enters both phases, which impedes to crystallization of the magnesium aluminotitanates phase; nickel-containing aluminomagnesium regions become centers of further crystallization of aluminomagnesium spinel. The spinel crystallization temperature, as well as mean sizes decreases with increasing the NiO content in the initial glass.