Synthesis of neodymium-doped yttrium aluminum garnet (YAG) nanocrystalline powders leading to transparent ceramics

We report on the synthesis of Nd:YAG nanoparticles by the coprecipitation technique and the optimum conditions for the processing of transparent ceramics. The powders prepared by the coprecipitation technique display significantly less agglomeration of crystallites, indicating higher sinterability. The crystallite size dependence on the calcinations temperature suggests the optimum temperature of 1100 °C, at which phase purity of the YAG nanopowder with the highest sinterability can be obtained. We have demonstrated that the optimum temperature for the vacuum-sintering is about 1785 °C for the uniaxially pressed samples to obtain transparent ceramic with uniform particle size of about 5–7 μm, and above this temperature, enormously large grain growth occurs, and facilitates large pores formation in the intergrain region that makes the ceramic fragile at the grain boundary.