Synthesis of ultrafine YAG:Tb phosphor by nitrate–citrate sol–gel combustion process

Ultrafine terbium-doped yttrium aluminum garnet (YAG:Tb) phosphor powders are prepared by a nitrate–citrate sol–gel combustion process using 1:1 ratio of citrate/nitrate. Phase evolution of the synthesized powder is determined by X-ray diffraction (XRD) techniques. Single-phase cubic YAG:Tb crystalline powder is obtained by calcinating the amorphous materials at 900 °C and no intermediate phase is observed. Transmission electronic microscope (TEM) morphology shows that the resultant YAG:Tb powders have uniform size and good homogeneity. The particle size of the product is investigated as a function of the calcination temperature. The photoluminescence (PL) spectrum of Tb3+ substituted for Y3+ in YAG with 5.0% content has been measured on samples calcined at different temperatures.