Microwave radiation heating synthesis and luminescence of SrWO4 and SrWO4:xEu3+ powders

SrWO4 and SrWO4:xEu3+ powders were synthesized by the method of microwave radiation heating. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and luminescence measurements. The XRD patterns show that SrWO4 and SrWO4:Eu3+ samples can be indexed as a pure tetragonal scheelite structure. The SEM results show that SrWO4 and SrWO4:Eu3+ samples have spherical morphologies. The surfactant of sodium dodecyl sulfonate (SDS) plays an important role in the formation of spheres. And Ostwald ripening may be the general mechanism in the process. The excitation spectrum of SrWO4 sample exhibits a broad absorption band peaked at 294 nm due to the charge-transfer transition in the WO42− anion. Upon excitation at 294 nm, SrWO4 sample exhibits a broad luminescence in the blue spectral range originating from the charge transfer transitions within the WO42− group. The excitation spectrum of SrWO4:Eu3+ sample includes a strong absorption band centered at 295 nm and weak peaks centered at 389 and 467 nm. The emission peaks of SrWO4:Eu3+ sample at 589 and 616 nm can be attributed to the 5D0→7Fj (j=1 and 2) transitions of Eu3+. The quenching concentration of Eu3+ in SrWO4:Eu3+ sample is 0.04.