A comparative study of the properties of terbium aluminum garnet powder sintered in air, vacuum and by laser irradiation

The structural and optical properties of terbium aluminum garnet (TAG) powder sintered (∼1100 °C) in air, vacuum (∼10−6 mbar) and with 70 W of unfocussed CW CO2 laser radiation, have been studied using X-ray powder diffraction (XRD), scanning electron microscopy (SEM/TEM), FTIR, optical absorption and photoluminescence techniques. Structural properties of TAG are found to be independent of the sintering procedure except that the pure TAG crystalline phase (Tb3Al5O12) is evolved in about 2 h in the case of laser sintering compared to 8 h needed in air sintering (by furnace) and 4 h needed in the case of vacuum furnace sintering. On the other hand, the absorption/emission intensity (300–600 nm region) of TAG samples sintered in vacuum is higher compared to that of laser/furnace sintering in air.