Their Thermoluminescence Research Articles

Luminescence and dosimetry investigations of Eu(III) doped Ca2CeVO6 novel double perovskite

A novel composition of vanadate double perovskite Ca2CeVO6 doped with Eu3+ was successfully synthesized using combustion synthesis, wherein the doping levels of Eu3+ ranged from 1 to 6 mol%. The Rietveld refinement of the powder X-ray diffraction (XRD) data confirmed the orthorhombic structure of the phosphors. Scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDAX) were employed to investigate the surface morphology and elemental distribution in the phosphor, respectively. Under the excitation at 280 nm and 467 nm, the phosphor exhibited strong down-conversion red photoluminescence (PL) emission, attributed to Eu3+ transitions (5D0-7FJ, where J = 0–3) originating from its 4f states. The intensity of PL emission shows increasing trend with increasing doping concentration. However, exceeding the threshold doping concentrations led reduction in PL intensity due to multipolar interaction effects. Additionally, the Eu3+ doped Ca2CeVO6 phosphors were subjected to irradiation with a radioactive 90Sr/90Y beta source to explore their thermoluminescence (TL) properties. Post-irradiation, the phosphors displayed prominent TL glow curves, with the most intense peak at around 94 °C, followed by peaks at 160 °C and 288 °C. The TL intensity of these peaks exhibited a linear dose response within the dose range of 1 Gy–50 Gy. Besides, the TL fading and reproducibility tests showed satisfactory results. Furthermore, Tmax-Tstop experiments revealed the presence of three trap centres within the trap depth range of 0.7–2.1 eV in the Ca2CeVO6:Eu3+ phosphor. Additionally, the glow curve deconvolution (GCD) was employed to determine trapping parameters, providing valuable insights into the TL behaviour of the phosphor. Overall, the results suggest that the novel phosphor under study holds promise for its applications in lighting devices and TL dosimetry (TLD).

Effect of the Crystalline Phase Type on the Thermoluminescent Response of ZrO2 Due to Different Synthesis Methods

ZrO2 samples were obtained using three different synthesis methods (Calcination, Co-precipitation and Hydrothermal). The samples were characterized to analyze the effect of the crystalline phase on their thermoluminescent (TL) and photoluminescent (PL) responses. The ZrO2 phase was analyzed by X-Ray diffraction (XRD) and Raman. Nanoparticle size distribution was obtained by scanning electron microscopy (SEM). For optical analysis, characterizations included absorbance measurements, where samples exhibited modifications in color centers, PL emission and experimental fluorescence lifetime decay ([Formula: see text] measurements. Additionally, their TL response was studied under UV (245[Formula: see text]nm and 385[Formula: see text]nm), and 6[Formula: see text]MV photon energy from LINAC excitation. The obtained results show the improvement of TL and PL properties due to ZrO2 phase while an amorphous ZrO2 synthesized by hydrothermal method is an excellent prospect to be used as TL material and it may be a promising scintillator material at 254[Formula: see text]nm.

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 5Gy 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.

Enhanced thermoluminescence, radioluminescence, and optically stimulated luminescence from lithium fluoride and silver nanoparticles composites

Plasmonic properties of metals can increase the sensitivity of ionizing radiation dosimeters. In this work, we study the plasmon resonance of silver nanoparticles (AgNp) to increase the optically stimulated luminescence (OSL) intensity of lithium fluoride (LiF) polycrystals. We produced LiF/Ag nanocomposites with different volumes of a silver nanoparticle dispersion and investigated their OSL response. We also investigated their thermoluminescence (TL) and radioluminescence/scintillation (RL) responses. X-ray diffraction (XRD), transmission electron microscopy (TEM) and UV–vis spectroscopy characterized the synthesized materials. XRD results clearly show the characteristic peaks of LiF and AgNps. TEM images revealed silver nanoparticles with diameters between 80 and 120 nm and LiF crystals with sizes between 1 and 5 μm. Reflectance spectroscopy showed a band around 420 nm, attributed to the plasmon resonance of silver nanoparticles. The responses of the OSL curves to X-ray irradiation were analyzed, showing higher OSL sensitivity with 14 mL AgNp, attributed to the AgNp plasmon resonance. A significant increase in TL and RL intensity could be observed for the LiF/Ag nanocomposites. TL, RL, and OSL results support that addition of AgNps do not lead to the creation of more and new traps or luminescent centers. The increase of TL and RL intensities is therefore related to the coupling of the luminescent centers with the AgNPs plasmons, in an energy-transfer mechanism (plasmon-coupled emission), whereas the enhanced OSL intensity directly correlates with the increased photoionization cross-section of the electronic traps under plasmon resonance conditions (plasmon-coupled excitation). Therefore, these results indicate that AgNp are potential candidates to increase the OSL, TL, and RL intensity from LiF dosimeters.

Investigations of thermoluminescence characteristics of SrAlBO4 :Eu3+ phosphors irradiated with gamma rays and carbon ion beam.

A series of SrAlBO4 :Eu phosphors doped with different concentrations of Eu (0.1, 0.3, 0.5, 0.7, 1.0mol%) was synthesized using a solid-state diffusion method, and their thermoluminescence (TL) properties were analyzed for gamma and carbon ion irradiation. The phase purity, morphological properties, vibrational features, and thermal stability of the prepared sample were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric/differential thermal analyzer (TG/DTA) techniques, respectively. The TL properties of the proposed materials showed broad dosimetric bands, peaking at 202°C for 0.12 kGy gamma irradiation. The highest TL intensity was obtained for a 0.7mol% concentration of Eu ions under gamma irradiation. Furthermore, the glow curve of the proposed materials showed a broad emission band, centred at 148°C under carbon ion beam irradiation and exhibited the highest emission intensity for a 0.1mol% Eu concentration. In addition, the dosimetric trapping parameters of the prepared samples such as symmetry factor, order of kinetics, activation energy, and frequency factor, were analyzed using various methods such as Chen's peak shape method, initial growth method, and the Ilich method. The obtained results of the samples showed the potential for dosimetric application.

Thermoluminescence properties of Dy3+-Doped Li2O–CaO–P2O5 glasses for neutron detection

In this study, we fabricated Dy3+-doped Li2O–CaO–P2O5 glasses using 6Li or nLi (nLi: containing 6Li or 7Li isotopes in natural abundance) to develop a new thermoluminescent material for neutron detection. Their thermoluminescence (TL) properties were investigated using X-ray and thermal neutron irradiation. TL glow peaks were observed at 366 K after X-ray irradiation, and the observed TL intensities of the nLi and 6Li glasses were similar, indicating that these materials have similar sensitivities to X-rays. A TL glow peak was observed at between 373 K and 400 K after neutron irradiation, and the TL intensities of the 6Li glass were significantly higher than those of the nLi glass, indicating that high-energy particles generated in the 6Li (n, α)3H reaction efficiently induced TL. The thermal neutron fluence and TL intensity derived from the 6Li (n, α)3H reaction in the neutron fluence range of 1.0 × 106–1.0 × 1011 neutrons/cm2 showed good linear correlation. These glasses are expected to be applied in TL dosimetry for X-rays, gamma rays, and thermal neutrons.

Analysis of thermoluminescence glow curve and evaluation of trapping parameters of cerium activated M2Al2SiO7 (M= Ca and Sr) phosphor for TLD application

A Series of Cerium activated aluminosilicate phosphors M2Al2SiO7 (M = Ca and Sr) were synthesized and their thermoluminescence (TL) characterization was carried out to investigate the dosimetry properties. A conventional high-temperature solid-state reaction method was adopted for the synthesis of phosphors. The structural characterization was done by powder X-ray diffraction (PXRD) tool, which confirms the phase formation of prepared samples. Concentration-dependent TL studies reveal that maximum intensity was obtained at 2 mol% and 0.5 mol% in Cerium doped Ca2Al2SiO7 (CASO) and Sr2Al2SiO7 (SASO) respectively. The analysis of the TL glow curve was carried out at this optimized concentration using E−Tstop, which represents that the glow curve is composed of six glow peaks superimposed on each other. The best-fit glow curve was carried out using the Glow Curve Deconvolution (GCD) methods and the best fit is observed with six superimposing peaks for both phosphors, which resemble with E-Tstop. TL curves in the E─Tstop method indicated that observed peaks are due to the existence of quasi-continuous distribution of traps. The trapping parameters were calculated and it reveals the presence of both shallow and deeper traps. Thermoluminescence responses vary linearly with dose rate and a very low fading was observed with storage time which suggests the application of the phosphors for low UV dosimetry.

Thermoluminescence and optically stimulated luminescence of Ba-doped Al2O3 produced by a modified sol-gel route

This work features the synthesis and characterization of Al2O3 phosphors doped with different concentrations of barium. The samples are produced by a modified sol-gel route, with glucose used as a chelating agent. The luminescent response of the phosphors is also evaluated through their thermoluminescence (TL) and optically stimulated luminescence (OSL). These optical properties are characterized with pellets obtained from the addition of Teflon to the phosphors. Through the TL analysis carried out with a heating rate of 10 °C/s, the samples reveal two intense TL glow peaks with different glow curve shapes when varying the dopant concentration of all the samples. By means of the TL emission curves of the pellets, activation energies associated with the transfer processes of the materials are determined. The phosphors present typical exponential OSL decay curves with a predominance of fast and medium components, indicating that the traps have a high photoionization cross section for blue light-emitting diodes.

Thermoluminescence properties of Ca2B2O5:Dy ceramics for neutron measurement

To develop thermoluminescent materials for neutron detection, 10B-enriched and 11B-enriched Ca2B2O5:Dy were prepared and their thermoluminescence (TL) properties were investigated after irradiation with X-rays, He ions and thermal neutrons. The TL of these materials was induced by X-rays and He ions and sensitivities to radiation are independent of the boron isotopes in the host materials. On the contrary, the TL intensity of the 10B-enriched sample was significantly higher than that of the 11B-enriched sample after irradiation with thermal neutrons. The high sensitivity to neutrons in the TL of the 10B-enriched sample is attributed to γ-rays and charged particles generated from 10B(n, α)7Li and 10B(n, α)7Li* reactions. In the neutron fluence range of the measurements (3.0 × 105 to 108 neutrons cm−2), the TL intensities attributed to 10B(n, α)7Li and 10B(n, α)7Li* reactions against thermal neutron fluence showed good linearity. In terms of detectable fluence, the new TL materials are more sensitive to neutrons than some existing Dy-containing TL materials.

The Potential Use of Car Windscreens for Post-Accident Dose Reconstruction in the Periphery of Nuclear Installations

Cars of a variety of brands are usually parked at a fixed but increasing distance in the periphery of nuclear installations. Herein we focus on the potential use of car windscreens for post-accident dose reconstruction from unplanned nuclear events and natural disasters, also in regard to unexpected events arising during large-scale use of radioactive and nuclear materials. The situation requires identification of analytical techniques that could both readily and reliably be used to assess absorbed dose, sufficient to prompt remedial action where necessary. Samples from three widely used car brands—Honda, Toyota and Proton—are studied in respect of their thermoluminescence (TL) yield. Key TL dosimetric features in the gamma-ray dose range of 1–100 Gy are examined. An ERESCO model 200 MF4-RW X-ray machine has also been used for energy response studies; a Harshaw 3500 TLD reader equipped with WinREMS software was used for the luminescence measurements. All brands exhibit linearity of TL yield versus dose, the samples from Honda showing the greatest response followed by that of the Toyota and Proton brands. The marked energy dependence reflects the effect of the strongly Z-dependent photoelectric effect. Signal fading was investigated over a period of 28 days, the Toyota and Proton brand windshield glass showing a relatively low loss at 52.1% and 52.6% respectively compared to a 56.7% loss for that of the Honda samples. This work forms the first such demonstration of the potential of car windshield glass as a retrospective accident dosimeter.

Study of optically stimulated luminescence and calculation of trapping parameters of K2Ca2(SO4)3:Eu nanophosphor

K2Ca2(SO4)3:Eu nanophosphor was synthesized by chemical coprecipitation method and annealed at different temperatures from 400 to 900 °C. The nanophosphor annealed at 600 °C showed cubic structure with crystallite size ~25 nm. TEM shows morphology of K2Ca2(SO4)3:Eu nanophosphor was in the form of nanorods having diameter ~20 nm and length of ~100–200 nm. These samples were irradiated with gamma radiation for the doses varying from 10 mGy to 10 kGy and their Thermoluminescence (TL) and continuous-wave optically stimulated luminescence (CW-OSL) have been studied. CW-OSL response was found to be maximal for the sample annealed at 600 °C. The TL glow curve of the nanophosphor apparently showed a major peak at around 160 °C accompanied by three low intensity peaks at ~75, 215 and 285 °C. The traps responsible for all the TL peaks in K2Ca2(SO4)3:Eu were also found to be OSL sensitive. The qualitative correlation between TL peaks and CW-OSL response suggested that the traps associated with low temperature peaks are responsible for fast decay and the traps associated with the higher temperature peaks are responsible for slow decay of the OSL signal. OSL response showed linear behavior up to 1 kGy and saturated with further increase in the gamma dose. The wide OSL response makes studied K2Ca2(SO4)3:Eu nanophosphor a good candidate for high dose measurement.

Thermoluminescence properties of Strontium borophosphate doped with Praseodymium and enhancement with uranyl codoping

Strontium borophosphate (SrBPO5) phosphors undoped and doped with Pr3+ and/or UO22+ were prepared by conventional high-temperature solid-state reaction method. The X-ray diffraction (XRD) and Raman spectroscopy studies confirmed the phase purity of the prepared samples. All the samples were irradiated with gamma radiation to study their thermoluminescence (TL) properties. The undoped SrBPO5 showed a very weak single glow peak at 415 K. whereas SrBPO5 doped with Pr3+/UO22+ exhibited multiple prominent glow peaks in the range of 395–460 K. Three glow peaks were also observed in case of SrBPO5 codoped with Pr3+ and UO22+. Interestingly, one of the three glow peaks were found to be in the range of 480–620 K and was very sensitive to the gamma radiation compared to the singly doped phosphor. The trap parameters were calculated for the glow peaks to understand the mechanism and order of kinetics. The dose-response of the dosimetric glow peak was studied in the range of 1 mGy to 1 kGy. TL emission spectrum showed characteristic emission of Pr3+ though no such emission was observed for UO22+. A probable TL mechanism has proposed for the TL emission coming from the SrBPO5 doped with Pr3+ and/or UO22+.

Thermoluminescence properties of Dy3+-doped CaO–Al2O3–B2O3 glasses for neutron detection

We fabricated neutron detection materials based on Dy3+-doped CaO–Al2O3–B2O3 glasses, including 10B-enriched (10B glass) and 11B-enriched (11B glass) glasses. The glasses were irradiated with X-rays, He ions, or neutrons, and their thermoluminescence (TL) properties were investigated. The TL properties of the 10B and 11B glasses after X-ray or He ion irradiation were similar. Meanwhile, the TL intensity of the 10B glasses was much larger than that of the 11B glasses. The TL peaks of 10B glasses were observed in the irradiation range of 109–1012 n/cm2, and the intensity increased monotonically with neutron fluence.

Effect of γ-irradiation on thermal and thermoluminescence properties of polystyrene/europium (III) oxide composite film.

In the present study, polystyrene:europium (III) oxide polymer films at a ratio of 95:5 wt% were prepared using a solution casting technique. These polymeric films were irradiated with 5, 25 and 50 kGy γ-radiation doses and their thermoluminescence (TL) and thermal properties were studied as a function of radiation dose. Analysis of Fourier transform infrared spectra revealed different modes of vibration and polymer-filler interaction. Reduction of vibrational modes with radiation dose was observed. The TL glow curve intensity was observed to increase with increasing radiation dose and to become broader in the 378 K and 444 K regions. Detrapping of electrons implied by the glow curve was caused by thermally induced macromolecular motion, concurrent with β-relaxation in polystyrene. The TL glow curve parameters were computed using a glow curve deconvolution method. Differential scanning calorimetry analysis indicated that the glass transition temperature (Tg ) increased with increase in dose, suggesting crosslinking of the polymer chain. Scanning electron microscopy analysis evidenced the change in surface morphology due to γ-irradiation.

Effect of MnO on structural, optical and thermoluminescence properties of lithium borosilicate glasses

MnO doped lithium borosilicate glasses of the composition 50B2O3–30SiO2-(20-x)Li2O-xMnO (where x = 0, 0.5, 1, 1.5, 2.0 mol %) was synthesized by melt-quench method. Structural and optical properties of these glasses were investigated using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and UV–Vis reflectance spectroscopic techniques. The glasses were exposed to γ-ray dose of 100 Gy and 1 kGy respectively and their thermoluminescence (TL) spectra were recorded up to a maximum temperature of 400 °C. The glow curve showed a single broad peak in the temperature range of 100–150 °C. The optimum response was observed for 0.5 mol% of MnO. The kinetic parameters have been calculated using peak shaped method, initial rise method and Glow curve convolution deconvolution (GCCD) method. The variation of kinetic parameters with the increasing concentration of MnO was studied. The mechanism of decrease in the TL output with the gradual increase in MnO content is explained upon the basis of the existence of different valence states of Mn ions in the present glasses. The glass with 0.5 mol% of MnO can be used for radiation dosimetry application due to good TL response.

Neutron-induced thermoluminescence properties of Tb<sup>3+</sup>-doped CaO–Al<sub>2</sub>O<sub>3</sub>–B<sub>2</sub>O<sub>3</sub> glasses

We fabricated neutron detection glasses, Tb3+-doped CaO–Al2O3–B2O3 glasses, including 10B-enriched (10B glass) and 11B-enriched (11B glass) glasses. The glasses were irradiated with X-rays, heavy particles, or neutrons and their thermoluminescence (TL) properties were investigated. The TL properties after X-ray or heavy particle irradiation were the same for the 10B and 11B glasses. Meanwhile, after neutron irradiation, the TL properties of the 10B and 11B glasses were significantly different. The TL intensity of the 10B glasses was higher than that of the 11B glasses, and the TL peak intensity of 10B (n, α) reaction had good linearity in the irradiation range of 109–1013 neutrons/cm2.

Thermoluminescence studies of CaSO4:Dy nanophosphor for application in high dose measurements

Nanorods of CaSO4:Dy (having diameter ∼20 nm and length ∼200 nm) were prepared by chemical coprecipitation method and their thermoluminescence (TL) characteristics were studied after annealing at different temperatures in the range 400–1000 °C. Microcrystalline material was also prepared through acid recrystallization method. TL glow curves of the nanocrystalline material annealed at 700 °C showed a major peak at around 283 °C. The effect of annealing temperature on the phase structure/morphology of particles was studied. Phase change was observed when CaSO4:Dy was annealed at different temperatures as confirmed by XRD and TG-DTA. It was observed from the TEM images that the nanomaterial originally in the nanorods form broke into nanoparticles due to strain developed by phase change on annealing at higher temperatures. The combined effect resulted in changes in TL glow curve structure. For better clarity the TL glow curves were further deconvoluted by Computerized Glow Curve Deconvolution (CGCD) method and kinetic trapping parameters were determined. It was found that the values of kinetic parameters also changed for the nanocrystalline material annealed at different temperatures. These were also compared with the corresponding values of the microcrystalline material. It was also observed that the TL intensity saturates at about 100 Gy in case of microcrystalline phosphor, while that in case of nanocrystalline phosphor did not do saturate even up to 5 kGy.

Synthesis and thermoluminescence of erbium-activated lithium niobate

Erbium-activated lithium niobate; 1, 2, and 4 mol% (LN-1, LN-2 and LN-4 respectively) were synthesized by solid-state method and their thermoluminescent (TL) properties were analyzed. The glow curve of LN-4 showed a maximum at 177 °C and its linear dose-response interval ranged from 50 to 350 Gy. Its TL intensity was two orders of magnitude greater compared to those of pure lithium niobate (LN), LN-1 and LN-2. We conclude that LN-4 is an interesting material for TL dosimetry applications.

Luminescence properties of europium doped lithium potassium tetraborate (Eu:LiKB4O7) single crystal for dosimetry applications

This paper describes an investigation of thermoluminescence radiation dosimetry characteristics of Eu:LiKB4O7 single crystal grown from Czochralski technique. The Eu:LiKB4O7 polycrystalline compound was synthesized by standard solid-state reaction method. Phase purity of both crystalline and polycrystalline materials was analyzed by powder X-ray diffraction technique. UV–Vis–NIR spectral analysis was carried out to study the optical characteristics of the grown crystal. Europium ion in the trivalent state in the host LiKB4O7 was confirmed by its characteristic emission at 613 nm due to the 5D0→7F2 transition. The (x, y) color chromaticity coordinates of Eu:LiKB4O7 was found to occur in the orange region of CIE 1931 diagram. The Eu:LiKB4O7 single crystalline samples was–irradiated by a Co-60 source at varying doses, suitable for radiation dosimetry applications, and their thermoluminescence (TL) properties was analyzed. The prominent TL glow peak of the grown crystal appears around 184 °C. The TL intensity increases linearly up to 156 Gy with excellent reusability and the fading was calculated for tenure of 60 days.

The role of Ti in charge carriers trapping in the red-emitting Lu2O3:Pr,Ti phosphor

Lu2O3:Pr,Ti storage phosphors were prepared by means of high temperature (1700°C) sintering both in a reducing atmosphere of the N2-H2 mixture (3:1 by volume) and in ambient air. Their thermoluminescent (TL) properties were presented and discussed. Pr singly-doped material showed only very inefficient TL. Ti co-doping boosted the TL efficacy, and the most potent TL was observed for ceramics containing 0.05mol% of Pr and 0.007mol% of Ti and made in the reducing atmosphere. Samples prepared in air produced noticeably less intense TL. The glow curves of both materials consisted of one broad asymmetric band with the maximum around 357°C for the heating rate of 4.7°C/s. The glow peaks could be fitted with three (reduced samples) or two (air-sintered) components. The latter lacked the high-temperature part of TL compared to the former. Tmax-Tstop experiments indicated that the TL is connected with continuous distribution of trap depths, which were estimated to cover the range of ~ 1.7 to 2.3eV, and their specific values were slightly dependent on the methodology. Anomalous dependence of the TL intensity on the heating rate made the semi-localized transition the likely mechanism affecting the TL properties of Lu2O3:Pr,Ti ceramics. The collected data allowed to construct vacuum referred binding energy (VRBE) level scheme with Pr3+ and Ti3+/4+ energy levels in the band gap of Lu2O3 host that could explain the TL mechanism in Lu2O3:Pr,Ti ceramics.