Production of nanopowder and bulk aluminate ceramic scintillators Review Article

The developed nanotechnology makes it possible to prepare lots of standard powders of Aluminates such as lutetium and yttrium orthorombic LuAlO3, YAlO3 (LuAP, YAP – perovskite), aluminum garnets Lu3Al5O12, Y3Al5O12 (LuAG, YAG) with cubic structure and aluminates with monoclinic structure Lu4Al2O9, Y4Al2O9, (LuAM, YAM). Powders of scintillation materials are prepared by sol-gel method, co-precipitation method and a combination of sol-gel method with combustion reactions. Crystallization process of LuAG phase starts at 900 °C. At lower temperatures, during the pyrolysis of the gel, amorphous powders have been produced. After pyrolysis of the gels without additives of aminoacetic acid a mixture of LuAG+Lu2O3 has been formed instead of LuAP. New phase of LuAP in a cubic form is detected. Diffraction peak profile analyzes and scanning electron microscope (SEM) investigations are performed to approximately establish grain size of the obtained powder. Thermogravimetry analysis (TGA) was carried out for detection of thermal effects in the range up to sintering temperature. Perovskite phases of aluminates have been synthesized via pyrolysis (at <900 °C) of the gel. Prepared nanopowders of aluminates are sintered using spark plasma processing. The best density of YAG has been detected at the following conditions of SPS process: 1650 °C/3 min/40 MPa.