Synthesis, Characterization and Thermoluminescence Properties of Rare Earth Ions Doped Silica Glass Prepared by Sol-Gel Technique

Abstract

Aims: The main aim of this work is to synthesize the silica glass (SiO2-glass) samples doped with different rare earths (RE) and then to study the thermoluminescence (TL) glow curve of these samples. Study Design: Rare earth doped samples namely silica glass (SiO2-glass) are synthesized by the sol-gel technique. Place and Duration of Study: Department of Physics (Atomic Physics Lab's, The University of Jordan), between May 2012 to May 2014. Methodology: This work presents a study of the role of an external impurities, namely dysprosium (Dy) and europium (Eu) with different concentrations on the mechanism of TL in SiO2-glasses. Results: The study of the best concentration for each doped silica, the basic TL feature main glow peaks occur in 156-320oC for (0.2 mol%) and 159-300oC for (0.002 mol%) with heating rate 2oC/s . At all β-dose levels, the intensities of the peaks are nearly linear in the dose range of o.5-2Gy. The fading rate of the :  Dy(0.002 mol%) response at room temperature is small. Variations of the normalized TL intensity as function of heating rate indicated reduction of TL-response accompanied by shift of TL-peaks towards higher temperatures. The kinetic parameters (activation energy E, frequency factors s) of all phosphors are determined and compared using two methods, with correlation of the trapping states to structure and comparison with values available from the literature. Conclusion: Rare earth doped SiO2-glass phosphors were successfully synthesized by sol-gel technique. Among all the dopants Dy(0.002 mol%) doped SiO2-glass phosphor showed the high intense and high temperature glow peaks (156oC up to 315oC) with good glow curve shape. In the case of SiO2-glass,Eu doped phosphor has given the good glow curve shape with glow curve structure. The glow peak of SiO2: Eu3+ is situated at 152oC.