Thermoluminescence kinetic parameters of different amount La-doped ZnB2O4

Synthesis, thermoluminescence characterizations, and photon attenuation parameters of MgAl2 O4 structure doped with different ions

In this work, different ion co-doped Mg1-x Al2 O4 nanophosphors, coded as M5Cr-5La A, M5Cr-5Cu A, M0.07Si-0.03Ce A, and M0.05Ti-0.05La A, where 5Cr-5La, 5Cr-5Cu, 0.07Si-0.03Ce, and 0.05Ti-0.05La representing the added ions (mol%), were prepared using the sol-gel method. Phase structure, transmission electron microscope (TEM) images, and element feasibility were checked using X-ray diffraction, TEM analysis, and energy dispersive X-ray (EDX) spectroscopy. Their thermoluminescence (TL) response was checked using a 5 Gy γ-test dose. The M0.05Ti-0.05La A sample was found to be best for the TL response with an ~1.1 times response compared with that of the MTS-700 commercial detector. A wide range of dose-responses for the M0.05Ti-0.05La A sample was found up to a 20 Gy γ-dose with the lowest detectable dose of ⁓23 μGy. Photon attenuation parameter results were Zeff ⁓10, which mean that the M0.05Ti-0.05La A sample could be considered as a near tissue equivalent material. Due to this study, the M0.05Ti-0.05La A sample can be considered as a promising detector for application in personal and medical dosimetric monitoring.

Thermoluminescence studies of zinc borate (ZnB2 O4 ) phosphor doped with rare earths for dosimetric aspects

A series of ZnB2 O4 phosphors doped with different concentrations of Eu and Dy (0.05 0.1, 0.2, 0.5, 1.0 mol%) and co-doped with Ce (1, 2, 5, 7, 10 mol%) respectively was prepared via the solid-state reaction technique and the thermoluminescence (TL) behaviour of gamma ray-irradiated samples was studied. The synthesized samples were irradiated with γ-rays for the dose range 0.03-1.20 kGy. The TL intensity variations with dose, dopant concentration, and the effect of co-doping were studied. The TL response curves for ZnB2 O4 :Eu3+ and ZnB2 O4 :Dy3+ , ZnB2 O4 :Eu3 ,Ce3+ and ZnB2 O4 :Dy3+ ,Ce3+ phosphor were observed. It was revealed that ZnB2 O4 :Eu3+ showed a linear TL behaviour for the dose 0.03-1.20 kGy and ZnB2 O4 :Dy3+ showed linearity for the gamma dose range 0.03-0.10 kGy. Furthermore, fading for all the samples was observed to be less than 10% for a storage period of 30 days. In addition to this, the trapping parameters, especially activation energies were evaluated using the Ilich method and the initial rise method. The activation energy values obtained from both methods were in complete agreement with each other.

Reinforcement of nanoporous lanthanum-doped zinc borate by vanadium selenide nanosheets for improved tribological activity

Nanoporous zinc borate (ZB) and 10% lanthanum-doped porous zinc borate (LZB) were synthesized to explore the role of porosity and doping in zinc borate during lubrication. HR-SEM, TEM, and HR-TEM authenticated nanoporous structures. The tribological properties of their blends with paraffin oil (PO) were compared by employing ASTM D4172 and ASTM D5183 norms on a four-ball tester. Vanadium selenide nanosheets (VSe2) were used to reinforce the structure of LZB for further advancement of the tribological properties. The superiority of the LZB/VSe2 over LZB and VSe2 nanosheets could be adjudged by tribological data. The porosity and lanthanum doping have yielded commendable tribological activity. The VSe2 nanosheets have strengthened the LZB matrix. The other constituent oxides of tribofilm from the LZB matrix, based on EDX analysis and XPS studies of the worn surface, ZnO, B2O3, La2O3, and V2O5, have abetted lubrication. The AFM and SEM investigations of wear track corroborated the tribological results.

Thermoluminescence glow curve deconvolution and kinetic parameter determination of samarium-doped lithium borosilicate glass

Thermoluminescence glow curves of gamma-irradiated samarium-doped lithium borosilicate glass were investigated. The number of overlapping peaks was determined using the repeated initial rise method. The glow curves were deconvoluted into four overlapping peaks. The trapping parameters such as activation energy E, frequency factor (s), and kinetic order (b) for each peak were determined. The obtained results indicated that the lithium borosilicate glass doped with samarium had four electron trap levels with the average activation energies of 0.82, 1.01, 1.21, and 1.31 eV. Thermal fading analysis of the individual peaks based on the deconvolution data was performed. The obtained results showed high thermal fading of the first peak, but high thermal stability of the second and third peaks compared with the other peaks. These results could be used to explain some observed properties such as high thermal fading and light sensitivity for this thermoluminescent material. Moreover, the obtained results may be helpful in minimizing fading corrections in dosimetric applications.

Thermoluminescence Studies of β and γ-Irradiated Geological Materials for Environment Monitoring

In the present report, thermally stimulated luminescence (TSL) of quartz and limestone samples irradiated with β and γ-rays has been investigated. Herein the formation of trap depths and calculation of kinetic parameters of β and γ - irradiated quartz and limestone samples were studied through thermoluminescence (TL) glow curve analyses. The quartz and limestone samples were collected from various sites of Chhattisgarh (Patharia and Dalli-Rajhara mines). The collected raw samples were annealed at 400 °C. The phase formation of collected samples is confirmed by X-ray diffraction studies. The grain sizes of the samples are determined by using Debye-Scherrer formula. TL glow curves of the collected samples were recorded for various doses of β and γ-rays. Kinetic parameters such as order of kinetics frequency factor and trap depth were calculated by employing CGCD methods. A comparative study on the TL properties of the geological materials under β and γ-irradiation was done. The trap model analysis was executed to determine the nature of traps responsible for dominant TL peaks of β and γ-irradiated limestone and quartz samples.

Thermoluminescence Characteristics of Terbium Doped Zinc Borates

In this work, structural and thermoluminescence (TL) characteristics for ZnB2O4:xTb3+ (x = 0.01, 0.02, 0.03, 0.04, 0.05, and 0.10 mole) phosphors were investigated. The phosphors were prepared via synthesis of nitric acid. The X-ray diffraction (XRD) studies show that the synthesized samples can be indexed to nearly single-phase cubic ZnB2O4. The TL characteristics following 90Sr beta irradiation (40 mCi) were studied. TL intensity is found to depend on Tb concentration. The optimal concentration of the doped Tb3+ is 0.03 mol in TL measurements. TL dose responses of the phosphors to beta doses of 0.143, 0.715, 1.43, 15, 30 and 60 Gy showed fairly linear behavior. The minimum detectable dose (MDD) value for ZnB2O4:0.04Tb3+ was found to be 87 mGy. The kinetic parameters of the ZnB2O4:0.03Tb3+ sample were estimated by the glow curve deconvolution, the initial rise, the curve fitting, and the peak shape methods. The results indicate that these phosphors are thought to be promising candidates as TL materials. The results provide valuable knowledge of the characteristics of Tb-doped ZnB2O4 for use in dosimetry research.

Luminescent properties and characterisation of LaB3O6:Eu3+ phosphor synthesized using the combustion method

Luminescent host materials which have LaB₃O₆ crystal structure were prepared and their structural and luminescent properties were analysed using the combustion method. Therefore, the measurements were performed at various temperatures. Phase impurity and optimum conditions were particularly determined at 900 °C for the host material prepared. Phase structures and morphological properties of the host material were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). LaB₃O₆ was observed to have monoclinic crystal structure. Photoluminescence (PL) method was used to analyse its emission properties. Thermoluminescence (TL) glow curves were recorded; starting from room temperature (RT) up to 450 °C at a constant increasing heating rate of 1 °C/s using a Lexsyg smart TL/OSL reader.

Effect of rare earth doping on optical and spectroscopic characteristics of BaZrO3:Eu3+,Tb3+ perovskites

This paper reports structural investigations of rare earth doped BaZrO₃ phosphors synthesized by Solid state reaction technique with varying concentrations of Eu³⁺ and Tb³⁺ from 0 mol% to 2 mol%. The synthesized phosphors show enhanced variable emissions in the visible region corresponding to different hypersensitive electronic transitions of Eu³⁺ and Tb³⁺ ions. With cubic structure confirmed in XRD analysis, the FESEM images show uniform grain connectivity and homogeneity of prepared samples. The TEM micrographs of the synthesized phosphors show agglomerated irregular structures. The synthesized phosphors were also subjected to FTIR, Raman, EDXS analysis along with studies of thermoluminescent and photoluminescent characteristics. On subjecting to 229 nm (UV) excitation, the phosphors show enhanced PL emissions corresponding to 571 nm (⁵D₀-⁷F₀), 591 nm (⁵D₀-⁷F₁), 615 nm (⁵D₀-⁷F₂) and 678 nm (⁵D₀-⁷F₄) hypersensitive transitions of Eu³⁺ ions and emission peaks at 489 nm (⁵D₄-⁷F₆), 539 nm (⁵D₄-⁷F₅), 589 nm (⁵D₄-⁷F₄) and 632 nm (⁵D₄-⁷F₃) accounting for electronic transitions of Tb³⁺ ions respectively. The computed average PL lifetime is 14.014 s. In the TL analysis, the second order of kinetics with the activation energy varying from 5.0 × 10^-1 eV to 6.6 × 10^-1 eV is reported. The maximum TL lifetime is estimated as 19.4985 min in the TL lifetime analysis.

Synthesis and stimulated luminescence property of Zn(BO2)2:Tb3

Zinc borate, Zn(BO₂)₂, doped with different concentrations of terbium (0.5-8mol%) was synthesized and polycrystalline samples were characterized by Scanning Electron Microscopy and X-Ray Diffraction. The Zn(BO₂)₂ was formed in the pure samples sintered at 750 and 800°C which has the body centered cubic structure, and a ZnB₄O₇ primitive orthorhombic phase was present. The thermoluminescent intensity was dependents on the thermal treatment (250-500°C) and also on the impurity concentration. The linear dose-response was obtained between 0.022-27.7Gy and 0.5-50Gy when the samples were exposed to beta and gamma radiation, respectively. The complex structure of the glow curves was analyzed by the Computerized Glow Curve Deconvolution method. The kinetics parameters were calculated assuming the general order kinetics model describing accurately the TL process. The glow curves of Tb³⁺-doped zinc borate phosphor were well deconvolved by six glow peaks. Zinc borate with 8mol% of impurity concentration exhibited an intense radioluminescent emission. The radioluminescent spectra show their maximum bands at 370, 490, 545 and 700nm related to the terbium ion in the zinc borate. These obtained results suggest that the terbium doped zinc borate is a promising phosphor for use in radiation dosimetry because of its high TL sensitivity to the ionizing radiation.

A new activator strontium for magnesium tetraborate: PL and TL studies

Strontium was used for the first time as an activator agent for magnesium tetraborate (MBO) and photoluminescence (PL) and thermoluminescence (TL) properties were determined using a spectrophotometer and a TL reader, respectively. The results proved that 0.25wt% Sr ratio played an important role in prolonging the afterglow and the phosphor gave the main TL peak with the highest intensity at 200°C like an ideal case. Therefore, it is worthwhile to carry out continuous and systematic research on it.

The effect of annealing and irradiation dose on the thermoluminescence glow peak of a monoclinic Gd2O3:Yb3+ phosphor

A monoclinic Gd₂O₃:Yb³⁺ phosphor was prepared using the combustion synthesis method.