Luminescence characteristics of Li2O-MgO-B2O3 doped with Dy3+ as a solid TL detector

Abstract

Enhancing the luminescence characteristics of rare earth doped borate glasses is the key issue in achieving an accurate dosimeter. Series of lithium and magnesium oxide modified borate glasses of compositions 20Li2O-(70-x)B2O3-10MgO-xDy2O3, where 0.3=x=1mol% are prepared using melt-quenching method. Synthesized samples are further activated with different concentration of Dy3+ and subjected to different doses by using a 60Co source. Effects of Dy3+ concentrations on luminescence behavior are examined. XRD patterns confirm the amorphous nature of all samples. A simple glow curve exhibits a peak at 190°C and optimum intensity for 0.5mol% of Dy3+ ions. Thermoluminescence (TL) properties including dose response and effective atomic number are determined. A good linearity in the dose response with correlation coefficient ~0.9977 and a tissue equivalent Zeff~8.71 is achieved. The room temperature photoluminescence (PL) spectra of these glasses under 350nm laser excitations reveal two enhanced peaks centered at 480nm (blue) and 573nm (yellow). The mechanism for the TL and PL enhancements are discussed and understood. These attractive luminescence features of prepared glasses may contribute towards the advancement of dosimetry.