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 Sr 3 Al 2 O 6 to SrAl 2 O 4 is found with increasing calcining temperature. The SAO-E sample calcined at 1400 °C for 2 h possesses a SrAl 2 O 4 single monoclinic phase (space group P 2 1 ). The light emission transition of SAO-E particles at low calcining temperature originated from both Eu 2+ and Eu 3+ ions where the trivalent europium ions were proved to be incorporated in the SrAl 2 O 4 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 SrAl 2 O 4 phase.