Synthesis and photoluminescence properties of SrLu2O4:Eu3+ superfine phosphor

Superfine powder SrLu2O4:Eu3+ was synthesized with a precursor prepared by an EDTA - sol-gel method at relatively low temperature using metal nitrate and EDTA as starting materials. The heat decomposition mechanism of the precursor, formation process of SrLu2O4:Eu3+and the properties of the particles were investigated by thermo-gravimetric (TG) - differential thermal analysis (DTA), X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) analyses. The results show that pure SrLu2O4:Eu3+ superfine powder has been produced after the precursor was calcinated at 900 °C for 2 h and has an elliptical shape and an average diameter of 80-100 nm. Upon excitation with 250 nm light, all the SrLu2O4:Eu3+ powders show red and orange emissions due to the 4f-4f transitions of Eu3+ ions. The highest photoluminescence intensity at 610 nm was found at a content of about 6 mol% Eu3+. Splitting of the 5D0-7F1 emission transition revealed that the Eu3+ ions occupied two nonequivalent sites in the crystallite by substituting Lu3+ ions.