Synthesis of nanocrystalline lutetium aluminum garnet powders by co-precipitation method

Lutetium aluminum garnet (LuAG) precursor was co-precipitated from a mixed solution of aluminum and lutetium nitrates using ammonia water as precipitant. Phase evolution and thermal decomposition of the precursor during calcination was studied by TG-DSC and XRD. The particle size and morphology of the synthesized powders were determined by TEM. It was found that the precursor was amorphous and transformed to pure LuAG at about 900 °C. The crystallization stage was characterized by an exothermic peak of DSC curve at 1032 °C. The resultant LuAG powders were loosely agglomerated with an average particle size 50 nm. The addition of small amount of ammonia sulfate to mixed solution reduces the agglomeration and produces more uniform spherical particle.