Crystallization of 2(Ca,Sr,Ba)O–TiO2–2SiO2 composition glasses

Abstract Crystallization was examined for glasses having chemical composition of 2(Ca,Sr,Ba)O–TiO 2 –2SiO 2 in which the CaO/SrO/BaO molar ratio varied. Powdered glass samples were pelleted into disks and sintered at 950 °C for 2 h. The major phase precipitated in the sintered samples was (Ca,Sr,Ba) 2 TiSi 2 O 8 and minor phase of perovskite such as CaTiO 3 or SrTiO 3 increased with CaO content in the samples containing more than 40 mol% of CaO in total CaO+SrO+BaO. Three regions having different slopes were found in linear relationships between SrO mol% and exothermal peak temperature on DSC curves or d [0 0 2] values determined by powder XRD method. These facts suggested that the major phase precipitated in each region was a solid solution containing a different amount of CaO, SrO, BaO and that these compositions varied depending on SrO content in the sample. The micro-crystalline structure, which could be useful in fabricating a dielectric dense body, was observed for samples containing 30–70 mol% of SrO.