Effects of CaO on crystallization properties in BaO–SrO–TiO2–SiO2 glass–ceramics

Abstract The role of calcium oxide (CaO) was investigated in the crystallization of BaO–SrO–TiO 2 –SiO 2 glass. The CaO dopant altered the oriented growth facets of crystal unit cells in the glass–ceramics. The crystallites are acicular in micron scale in the samples having as small as 1% CaO dopant, but are long granular in the nanometer scale in the sample without CaO. The glass–ceramics which have nano crystallites are observed with a less crystallization density qualitatively, a higher transmissivity in the wavelength range of 200–2600 nm, and 30% lower piezoelectric coefficient, d 33 , at 9.5 ± 0.3 pC/N than those glass–ceramics having CaO in the study.