Thermal Stability of SrAl2O4: Eu2+, Dy3+ with Long Afterglow Phosphorescence

Oxide phosphorescent phosphor has an wide application in ceramic art and decoration due to its chemical and mechanical properties. Here, phosphorescent properties of strontium aluminate phosphor (SrAl2O4 : Eu (2+), Dy3+) emitting yellowish-green light was investigated with thermal treatment at 1250 degrees C under air and reducing atmosphere. The characterizations of thermally treated samples were analyzed using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive Xray spectroscopy (EDX), fluorescence spectrometer. SrAl2O4 : Eu2+, Dy3+ still showed a good phosphorescent properties after annealing process in reducing atmosphere, while phosphorescence of SrAl2O4 : Eu2+, Dy3+ annealed in air seriously degraded, due to oxidation of Eu2+ to Eu3+ ions. It was also observed that SrAl2O4: Eu2+, Dy3+ annealed in reducing atmosphere emitted yellowishgreen light during 3 h after being exposed to sunlight.