Preparation and Characterization of Luminescent Materials BaWO4:Eu3+
|Course||Physical and chemical|
|Keywords||rare earth luminescent BaWO4 chemical precipitation high temperature-energy ball milling|
Since the 20th centrary, the Luminescent materials have been a hot spot in luminescent materials research, for example, successful development of the lighting source light emitter diode (LED) and the rare earth three primary color fluorescent lamps, so it is becoming a lot of scholar’s goal to find out a luminescent material which has high luminescence and stability. In this paper, chemical precipitation method and high temperature-energy ball milling method are adopted to synthesize red luminescent materials powder (BaWO4:Eu3+), and some research and discussion have been done in the best preparation technology.The precursors were synthesized by chemical precipitation method with sodium tungsten oxide, barium nitrate and europium oxide as raw materials. According to the DSC-TGA curves, the hot decomposition of precursor was determined, and the reasonable calcination temperature of powders was made. BaWO4:Eu3+ powders were prepared by controlling the pH value of solution, changing the method of Eu3+ doped, the precipitation temperature, pre-firing temperature, the calcination temperature, heat preservation time and the concentration of Eu3+ doped. The BaWO4:Eu3+ powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and emission spectrum. Experimental results showed that the best preparation techniques of BaWO4:Eu3+ powders were that the pH value was 7, the precipitation temperature was 50℃, the pre-firing temperature was 200℃, the calcination temperature was 900℃, the heat preservation time was 3 h and the concentration of Eu3+ doped was 13%mol. Under these conditions, the luminescence of powders is the best.The BaWO4:Eu3+ powders were also prepared by high temperature-energy ball milling method and choosing the precursors synthesized by chemical precipitation method as raw materials. BaWO4:Eu3+ powders were synthesized by changing the ball milling temperature, the ball milling time, balls/material weight ratio and the concentration of Eu3+ doped. The BaWO4:Eu3+ powders were characterized by X-ray diffraction, scanning electron microscopy and emission spectrum. Experimental results showed the best preparation techniques of BaWO4:Eu3+ powders were that the ball milling temperature was 700℃, the ball milling time was 2 h, the balls/material weight ratio was 15:1 and the concentration of Eu3+ doped was 15% mol. Under these conditions, the luminescence of powder is the best.By comparing the above two experiments, We can get a conclusion that high temperature-energy ball milling method can not only synthesize BaWO4:Eu+ powder with simple preparation techniques and in a lower temperature, but also can get a better luminescent performance in the condition of the same temperature and the same Eu3+ doping quantity.