Synthesis and characterization of (MgO,BaO)–Al2O3–SiO2 glass-ceramics from the sol–gel process

Abstract The current investigation is concerned with the preparation of dense bulk glass-ceramics with the composition of Mg1−xBaxAl1.9Si2.25Oy by the sol–gel method. Dense samples were obtained by sintering the xerogel glass powders, which were prepared from Ba–isopropoxide, Al–sec-butoxide, Mg–methoxide, and fumed silica. The local inhomogeneity due to the fumed silica resulted in a complex microstructure in the samples. The predominant phase in the samples fired at 1000°C varies from cordierite to barium osumilite and hexacelsian with increasing BaO content. Dielectric properties of the sintered bulk samples were found to closely follow their relative densities.