Effect of heat-treatment temperature on optical properties of Ba 2TiSi2O8 nanocrystallized glasses

Abstract

Nanocrystallized glasses with the composition of 40BaO · 20TiO 2 · 40SiO2, stoichiometric to fresnoite (Ba 2TiSi2O8), have been prepared by heat-treatment at various temperatures, and their optical properties, second-harmonic generation (SHG) and photoluminescence (PL), have been examined. The glass subjected to the heat-treatment at 760°C for 1 h showed a dense formation of Ba2TiSi2O8 crystals with the dimension of 200-300 nm, and maintained a visual transparency. Visible green light corresponding to SHG at 532 nm was confirmed in the transparent Ba 2TiSi2O8 nanocrystallized glasses. The maximum second-harmonic intensity in the nanocrystallized samples was on the order of 1/100 when compared to that of an α-quartz single crystal. Furthermore, the bluish white PL with a peak at the wavelength of about 470 nm was also visually observed in samples heat-treated at 750-800°C.