Effects of cerium oxide and cerium sulfate on the optical behavior of synthesized garnet glass ceramics

In this study, the YAG silicate glasses containing the cerium sulfate and cerium oxide salts (17YO3-33Al2O3-40SiO2-2AlF3-3NaF-2CeO2-3B2O3), separately were produced by melting method and glass ceramics were produced by heat treatment of base glasses. According to Photo Luminescence spectrums of both glasses there were emissions in the range of 466 and 435 nm wavelengths related to cerium ions. It was shown that by heating treatment, garnet crystal (in sulfated sample) formed less than the sample with cerium oxide. The emission spectra of both glass-ceramics, when excited at 240 nm, fall within the wavelength range of 460 nm. Also, the 534 and 660 nm emissions wavelengths were obtained by 340 nm wavelength excitation. Heat treatments were done by oxide atmosphere in tubular furnace (single step), SPS sintered powder and in hydrogen atmosphere (by two steps heating). According to XRD results the 24 hrs. heat treating time and the 1060 °C temperature affect the entry of cerium into the garnet structure. Finally, by comparing the spectroscopic results the optical response of the garnet glass-ceramic synthesized in the hydrogen atmosphere was obtained at 400 nm wavelength that indicated this garnet can be applied in the LED industry.