Effect of Eu doping on the thermoluminescence of UV and gamma irradiated Mg₂B₂O₅ nanophosphors

Abstract

This article presents the effect of europium (Eu) doping on the thermoluminescence (TL) of ultraviolet (UV‐254 nm) and gamma irradiated triclinic Mg2B2O5 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 Mg2B2O5. 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 Mg2B2O5 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 Mg2B2O5 nanophosphors can be tuned for UV and gamma dosimetry.

Effect of Eu3+ doping on the structural, optical, and photoluminescent properties of LiGa5O8 phosphor

“…This decrease in the bandgap of these doped samples can be attributed to the formation of new energy states near the bottom of the conduction band and near the top of the valence band. This is often observed due to the presence of shallow-level donor impurities 35 and a significantly higher difference in ionic radius between the dopant ion and the replaced atomic site, 36 which has a major effect on the 5 mol% doped sample. For the samples with a doping concentration of 1–4 mol%, the combined effect of the formation of new energy levels and the effect of the high optical bandgap of the doped rare earth ion can be observed, 37 with the effect of the former still being dominant.…”

“…This decrease in the bandgap of these doped samples can be attributed to the formation of new energy states near the bottom of the conduction band and near the top of the valence band. This is often observed due to the presence of shallowlevel donor impurities 35 and a significantly higher difference in ionic radius between the dopant ion and the replaced atomic site, 36 which has a major effect on the 5 mol% doped sample.…”

Magnesium Borates: The Relationship between the Characteristics, Properties, and Novel Technologies

“…In nuclear research, dehydrated forms of magnesium borates such as MgB 4 O 7 , Mg 2 B 2 O 5, and MgB 2 O 4 are generally preferred. This can be explained by the decreasing hygroscopicity at reaction temperatures higher than 950°C and the ease of solidstate synthesis methods [11,[23][24][25]. Souza et al [26] compared the thermoluminescence features of the synthesized magnesium borates in liquid-state and solid-state conditions and indicated better results of dehydrated samples [26].…”