Synthesis of Y3Al5O12:Eu3+ phosphor by sol-gel method and its luminescence behavior

The Eu3+-doped Y3Al5O12 phosphor ultrafine powders were synthesized by the sol-gel method using metal alkoxide at the lower temperature of 1000 degrees C. The formation process and structure of the phosphor powders were investigated by means of TG-DTA, XRD and SEM. It has been found that the phosphor powders were amorphous up to 700 degrees C and changed into the single phase YAG at about 1000 degrees C, that is, 600 degrees C lower than that required for the constituent oxide mixtures. The resulting ultrafine, phase-pure, cubic yttrium aluminum garnet (YAG) phosphor powders were obtained. In the course of the phosphor transformation from non-crystalline state to crystalline state, both the emission intensity and the site symmetry of Eu3+ in the phosphors varied noticeably. The Eu3+ emission intensity of D-5(0) --> F-7(1) and D-5(0) -->F-7( )2 versus Eu3+ concentration and sintering temperature was studied. (C) 1998 Elsevier Science S.A.