The crystallization and structure features of glass within the K2O–MgO–CaO–Al2O3–SiO2-(BaO) system

Abstract The effect of the BaO addition on the microstructure and structure of the glasses from the K2O–MgO–CaO–Al2O3–SiO2-(BaO) system was investigated in this study. The results were obtained by testing the crystallization capability of the glasses during the fast-firing cycle. Thermal analysis proved a high tendency to crystallize the tested glasses/frits. X-ray analysis showed the presence of diopside and anorthite as the main crystalline phases in all glazes obtained from the tested glasses. Microscopic observations showed that barium oxide introduced in the range of 0.4–2.1 mol% into the examined system strongly influences the number and size of crystalline phases. The introduction of 2.1 mol% BaO into the composition also resulted in crystallization of celsian. The thermal characteristic of the glasses was carried out using differential scanning calorimetry (DSC) and the crystalline phases were determined by X-ray diffractometry. The glaze microstructure was investigated by scanning (SEM) and transmission electron (TEM)microscopy. Additional information on the structure of frits was derived from mid-infrared (MIR) and Raman spectroscopy.