Synthesis and photoluminescence properties of SrLu 2O 4:Eu 3+ superfine phosphor

Abstract

Superfine powder SrLu 2O 4:Eu 3+ 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 SrLu 2O 4:Eu 3+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 SrLu 2O 4:Eu 3+ 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 SrLu 2O 4:Eu 3+ powders show red and orange emissions due to the 4f–4f transitions of Eu 3+ ions. The highest photoluminescence intensity at 610 nm was found at a content of about 6 mol% Eu 3+. Splitting of the 5D 0– 7F 1 emission transition revealed that the Eu 3+ ions occupied two nonequivalent sites in the crystallite by substituting Lu 3+ ions.