M. H. A. Mhareb

Thermoluminescence dosimetry properties and kinetic parameters of lithium potassium borate glass co-doped with titanium and magnesium oxides.

Lithium potassium borate (LKB) glasses co-doped with TiO2 and MgO were prepared using the melt quenching technique. The glasses were cut into transparent chips and exposed to gamma rays of (60)Co to study their thermoluminescence (TL) properties. The TL glow curve of the Ti-doped material featured a single prominent peak at 230 °C. Additional incorporation of MgO as a co-activator enhanced the TL intensity threefold. LKB:Ti,Mg is a low-Z material (Z(eff)=8.89) with slow signal fading. Its radiation sensitivity is 12 times lower that the sensitivity of TLD-100. The dose response is linear at doses up to 10(3) Gy. The trap parameters, such as the kinetics order, activation energy, and frequency factor, which are related to the glow peak, were determined using TolAnal software.

Physical and optical properties of Li2O-MgO-B2O3 doped with Dy3+

The study on the optical properties of alkali borate glasses doped with rare earths is an interesting area of research. Dysporosium doped lithium magnesium borate glasses were prepared by melt-quenching technique with dysporosium concentration varying from 0.3 to 1.0 mol %. Physical and optical properties of Lithium Magnesium Borate doped with different concentration of Dy3+ were observed based on its physical parameters, emission spectra and absorption spectra. The absorption spectra of this study exhibits eight absorption bands with hypersensitive peak at 1260 nm (6H9/2). Two emitted spectra transitions were also observed at 4F9/2 → 6H15/2, 4F9/2 → 6H13/2. Lastly, important physical parameters for each concentration of dopant such as density, ions concentration, polaron radius, inter-nuclear distance, refractive index, oscillator strength and other parameters were determined.

Thermoluminescence properties of lithium magnesium borate glasses system doped with dysprosium oxide

We report the impact of dysprosium (Dy(3+)) dopant and magnesium oxide (MgO) modifier on the thermoluminescent properties of lithium borate (LB) glass via two procedures. The thermoluminescence (TL) glow curves reveal a single prominent peak at 190 °C for 0.5 mol% of Dy(3+). An increase in MgO contents by 10 mol% enhances the TL intensity by a factor of 1.5 times without causing any shift in the maximum temperature. This enhancement is attributed to the occurrence of extra electron traps created via magnesium and the energy transfer to trivalent Dy(3+) ions. Good linearity in the range of 0.01-4 Gy with a linear correlation coefficient of 0.998, fading as low as 21% over a period of 3 months, excellent reproducibility without oven annealing and tissue equivalent effective atomic numbers ~8.71 are achieved. The trap parameters, including geometric factor (μg), activation energy (E) and frequency factor (s) associated with LMB:Dy are also determined. These favorable TL characteristics of prepared glasses may contribute towards the development of Li2O-MgO-B2O3 radiation dosimeters.

The effect of europium oxide impurity on the optical and physical properties of lithium potassium borate glass

The most hosts that is utilized in scientific application is borate glass. By using melt-quenching technique, five samples of lithium potassium borate (LKB) doped with different concentration of europium oxide (Eu2O3) were prepared. To investigate the influence of dopant on the optical and physical characteristics of the proposed glass, two methods have been applied (XRD, PL). The amorphous nature was confirmed by X-ray diffraction (XRD). The physical parameters of the glass matrix doped by different oxidation state have been analyzed, these parameters are density, molar volume, ion concentration, inter-nuclear distance, and polaron radius. The exchange in the concentration of Eu3+ indicated the influence of Eu as a dopant on the photoluminescence (PL) emission of LKB glasses. The emission spectrum of LKB:Eu3+ show a chain of emission bands, which are attributed to 5D0-7Fr (r = 1–4) transition of Eu3+. The luminescence studies showed four peaks 590 (yellow), 613 (orange), 650 (red), and 698 nm (red) for all samples except sample 0, the high luminescence efficiency is in emitting orange light at 613 nm.

Structural and optical properties of lithium sodium borate glasses doped with Sm3+ ions

Absorption and emission spectra of Sm3+ doped lithium sodium borate (LNB) have been reported. The samples were prepared by the melt-quenching technique and characterized by X-ray diffraction (XRD), diffraction thermal analysis (DTA), Fourier transforms infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FESEM). From the thermo-grams spectrum, glass transition (Tg), crystallization (Tc) and melting temperatures (Tm) have been evaluated. Direct and indirect optical band gaps have been calculated based on the glasses UV absorption spectra. These glasses have shown strong nine absorption bands with hypersensitive transition at 1221 nm (6H5/2→4H3/2) and five emission bands for the transition at 4I7/2→6H13/2 (green color), 4I7/2→6H7/2 (orange color), 4I7/2→6H9/2 (orange color), 4I7/2→6H11/2 (red color) and 4I7/2→6H13/2 (red color) with performing an excitation of 400 nm. The oscillator strengths, refractive index, ions concentration, polaron radius and other parameters have been calculated for each dopant.

Photoluminescence and thermoluminescence properties of Li2O-Na2O-B2O3 glass

UNLABELLED Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. HIGHLIGHTS The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.

Photoluminescence and thermoluminescence properties of Li2O-Na2O-B2O3glass: Photoluminescence and thermoluminescence properties

UNLABELLED Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. HIGHLIGHTS The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.

Photoluminescence and thermoluminescence properties of Li₂O-Na₂O-B₂O₃ glass.

UNLABELLED Influence of Nd(3+) concentration on the optical and thermoluminescence (TL) properties of melt-annealed synthesized 10 Na2O: 20 Li2O: (70-x) B2O3 : xNd2O3, where 0.1≤ x ≤0.7 (LNB) glasses are determined. The absence of sharp peaks in X-ray diffraction patterns confirms the amorphous nature of the prepared glasses. The photoluminescence spectra under 800 nm laser excitations at room temperature exhibit three prominent peaks centred at 538, 603 and 675 nm corresponding to the transitions of (4)G(7/2) → (4)I(9/2), [(4)G(7/2) → (4)I(11/2), (4)G(5/2) → (4)I(9/2)] and [(4)G(7/2) → (4)I(13/2), (4)G(5/2) → (4)I(11/2)], respectively. The TL glow curve exhibits a prominent peak (T(m)) at 180°C. The best performance of the prepared glass was found at 0.5 mol% of Nd2O3. We achieved a good linearity of TL response against dose between 0.5 to 4.0 Gy. The calculated value of the effective atomic number, Z(eff), is 7.55 which is nearly tissue equivalent (Z(eff) = 7.42). These promising features demonstrate the capability of the aforementioned glass to be used as a radiation dosimeter. HIGHLIGHTS The thermoluminescence and optical properties of new compositions of lithium sodium borate glasses doped with Nd(3+) ions were reported. Attractive features were obtained from the TL, PL and UV-Vis light analysis. Three upconversion luminescences permitting green, orange and red emissions were observed.