Effect of Eu doping on the thermoluminescence of UV and gamma irradiated Mg2 B2 O5 nanophosphors

Abstract

This article presents the effect of europium (Eu) doping on the thermoluminescence (TL) of ultraviolet (UV-254 nm) and gamma irradiated triclinic Mg₂ B₂ O₅ nanophosphors. The diffuse reflectance predicts slight decrease in band gap from 5.18 to 4.99 eV with increasing Eu (1%, 3%, and 5%) content in Mg₂ B₂ O₅ . The TL glow curves of UV irradiated samples comprised of a main peak around 500 K with weak intensity peak/shoulders in low temperature region. Interestingly Eu (3%) doped Mg₂ B₂ O₅ shows maximum TL intensity with suppression of low temperature shoulder peaks and almost linear UV dose dependent TL response. However, in the case of gamma irradiated Eu (1% and 3% doped) samples, TL glow curve comprises of a main peak around 425-445 K and closely lying peak around 500-515 K with relatively lesser intensity. In case of Eu (5%) doped samples, TL peak around 508 K starts dominating over peak around 425 K. TL of both UV and gamma irradiated samples showed the presence of various deep and shallow defect states within the bandgap of materials having different kinetic parameters, which were determined using TLanal software based on Kiti's general order equation. The present study shows that Eu doped Mg₂ B₂ O₅ nanophosphors can be tuned for UV and gamma dosimetry.

Keywords: Mg2B2O5 nanophosphors; UV; band gap; gamma; thermoluminescence.