Nanopowders and crystals in (Y1−xNdx)3Al5O12 system: Preparation and properties

Total substitution of yttrium by neodymium assuming garnet phase of the YAG:Nd was investigated. Components were synthesized by sol-gel method and the limit solubility of Nd in the single phase of YAG was equal to 27.5 at.%. At higher concentration of Nd two phases were found, garnet and perovskite. Samples of Nd-Al-O stoichiometric garnet exhibit only the perovskite phase. Crystals were grown by micro-pulling method and at concentration of Nd larger than 1 at.% Nd, the crystals show two phases: garnet and solid solution of perovskite. Luminescence decay curves of nanopowders depend on thermal treatment. The increase in Nd3+ concentration in YAG matrix over 10 at.% is not recommended for optical applications. It was found that the lifetime value for the powder YAG sample containing 1% of Nd3+ is larger than the reported lifetimes for sample of the YAG single crystal.