Structure and non-linear optical properties of BaO–TiO2–SiO2 glass containing Ba2TiSi2O8 crystal

The BaO–TiO2–SiO2 crystallized glass containing Ba2TiSi2O8 crystal phase was examined using X-ray diffraction (XRD) measurement and Maker fringe technique. It has been found that the crystallized glasses with a composition of close to the stoichiometric Ba2TiSi2O8 showed bulk crystallization, whereas other crystallized glasses with non-stoichiometric composition of Ba2TiSi2O8 showed surface crystallization. The parameter ΔT, the difference in temperature between the crystallization onset and the glass transition temperature, strongly affects the crystallization behaviors of the present BTS glasses. The 30BaO–20TiO2–50SiO2 transparent surface crystallized glass with strong c-oriented Ba2TiSi2O8 phase showed its second-order non-linear optical constant, d33 = 6.1 pm/V.