Influence of calcining temperature on photoluminescence and triboluminescence of europium-doped strontium aluminate particles prepared by sol-gel process

On the basis of a new modified base-catalyzed sol-gel process and a careful investigation in the structure, this study systematically discussed the effects of the calcining temperature on the microstructure and luminescent properties of europium-doped strontium aluminates (SAO-E). A phase transformation from Sr3Al2O6 to SrAl2O4 is found with increasing calcining temperature. The SAO-E sample calcined at 1400 degreesC for 2 h possesses a SrAl2O4 single monoclinic phase (space group P2(1)). The light emission transition of SAO-E particles at low calcining temperature originated from both Eu2+ and Eu3+ ions where the trivalent europium ions were proved to be incorporated in the SrAl2O4 phase, which gradually transformed into the divalent ions with increasing calcining temperature. The strong photoluminescence and triboluminescence were obtained without luminance temperature-degradation in this single monoclinic SrAl2O4 phase.