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 (similar to 1100 degrees C) in air, vacuum (similar to 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. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.