| Abstract: | Lutetium aluminium garnet (LuAG) ceramics as host materials has been widely used in lighting, laser, displaying and scintillators after doping different rare earth ions. Right selection of raw powder and controlling its characteristics during the preparation can greatly improve the optical quality of transparent ceramics. In this paper, the influence of different pretreatment temperatures of commercial Lu2O3 powders in oxygen atmosphere on solid state sintering of LuAG ceramics was systematically investigated. The pretreatment gradually decreased the specific surface area of Lu2O3 powders and greatly removed the absorbed impurities, which seriously deteriorated the optical quality before. The mean particle size increased from 4.53 to 5.66 μm, and the in-line transmittance of samples (Thickness = 2 mm) at 1064 nm was 68.4% for the pretreated Lu2O3 powder at 1000 °C without any sintering additives. Further increase of pretreatment temperature would lead to the coarsening of Lu2O3 powders and the decrease of sintering activity, which finally resulted in a large number of micro pores in LuAG ceramics. These results revealed that the pretreatment of Lu2O3 powders has prodigious impact on the optical quality of LuAG transparent ceramics, and the adsorbed materials should be removed as much as possible for their applications in lasers or lighting. |
