Synthesis of CaWO4:Eu3+ phosphor powders via a combustion process and its optical properties

Using citric acid as chelating agent and fuel, ammonium nitrate as fuel, boric acid as flux material and silica as supports, persistent phosphor CaWO4:Eu3+ has been prepared via a combustion process, which formed voluminous white powder. The persistent phosphor was further investigated by X-ray diffractometer (XRD), fluorescence spectrophotometer (PL) and transmission electron microscopy (TEM). XRD analyses indicate that the crystalline calcium tungstate has been synthesized when ignited at 500 degrees C. The PL results showed the highest intensity of emission spectrum obtained at 800 degrees C, the optimal contents is 0.7CaWO(4):0.3Eu(3+) incorporated into silica which could enhance luminescence intensity of CaWO4:Eu3+. The average particle sizes as measured by TEM are ranged in 50 to 100 nm, which could extend the application of this phosphor. (c) 2007 Elsevier B.V. All rights reserved.