Luminescence characteristics of newly-developed MgB4O7:Ce3+,Na+ phosphor as an OSL dosimeter

Abstract

In this study, dosimetric properties of Ce3+ and Na+ doped magnesium tetraborate (MgB4O7) phosphors synthesized by the solution combustion synthesis (SCS) method were investigated using optically stimulated luminescence (OSL) technique to develop OSL radiation dosimetry. The concentrations of Ce3+0.3%wt and Na+1–14%wt dopants in MgB4O7 were incorporated into it to improve the efficiency of luminescence. The results showed that the effect of Na+ substitution on MgB4O7:Ce3+0.3%wt lattice induced a remarkable improvement of both its thermoluminescence (TL) and OSL signals. The highest OSL signal of the synthesized phosphor was recorded at the MgB4O7:Ce3+0.3%wt,Na+14%wt phosphor. Its TL glow curve consists of two peaks located at ~70 °C and ~230 °C with a heating rate of 2 °C/s. These TL peaks were found to be optically sensitive to blue light excitation (λ = ~470 nm). X-ray diffraction (XRD), scanning electron microscopy (SEM), radioluminescence (RL) techniques have been employed to characterize the synthesized phosphor. The XRD pattern of MgB4O7:Ce3+0.3%wt,Na+14%wt phosphor with orthorhombic phase was observed in the specimen sintered at 900 °C. The RL spectrum of the MgB4O7:Ce3+0.3%wt,Na+14%wt phosphor revealed a strong and a weak emission peak located UV and red regions, respectively. OSL dosimetric properties of the phosphor were studied under beta radiation of 90Sr/90Y. The phosphor exhibited good linearity between 1 and 100 Gy. Minimum detectable dose (MDD) of the phosphor was calculated as 0.73 mGy. A good reusability property was determined up to 20 experimental cycles with a deviation of 4.5%. Short-time fading up to 24 h and long-time fading up to 4 weeks were studied. The results shows the MgB4O7:Ce3+0.3%wt,Na+14%wt phosphor can be proposed as a potential OSL dosimetry for radiation dose measurements in medicine using OSL technique.