Thermoluminescence Properties Research Articles

On the thermoluminescence characteristics of NaF and KCl

Thermoluminescence (TL) properties of NaF and KCl are investigated in order to assess their suitability as radiation dosemeters for retrospective dosimetry. TL measurements were made on samples irradiated to different doses (1–20 Gy) and heated at a rate ranging from 0.4 to 4 °C/s in a TL/OSL reader. The TL glow curves of NaF, readout at 1oCs−1, exhibited six apparent peaks around 38.7 ± 1.4, 63.5 ± 0.5, 105.5 ± 0.4, 237.5 ± 0.8, 299.0 ± 1.0 and 347.5 ± 0.7 °C with a shoulder around 168.0 ± 2.3 °C. Those of KCl have three clearly identifiable peaks around 44.0 ± 0.3, 95.3 ± 0.8 and 160.5 ± 0.7 °C. Glow curve deconvolution, however, revealed that the glow curves of NaF and KCl are best fitted with nine and five glow peaks respectively. In NaF, all the peaks exhibited linearity of dose-response in the entire dose range considered in this study. Only the peaks around 95.3 ± 0.8 and 160.5 ± 0.7 °C exhibited linear dose-response in the entire dose range for KCl. In NaF, there was thermal quenching of the TL responses of the peaks around 63.5 ± 0.5, 105.5 ± 0.4 and 237.5 ± 0.8 °C, and thermal enhancement of responses for peaks around 299.0 ± 1.0 and 347.5 ± 0.7 °C. With respect to KCl, the TL responses of all the peaks exhibited thermal enhancement as heating rate was increased. The activation energies associated with the thermal enhancement and quenching of the peaks’ TL responses are presented. The repeated use of an aliquot of NaF five times for dose measurements resulted in an acceptable variation in sensitivity, on the other hand the sensitivity of KCl decreased with increasing number of repeat use. The activation energy of the electron traps associated with the glow peaks in both crystals calculated in this study are comparable to previously published values. Both crystals can be used for retrospective dosimetry however change in sensitivity with repeat use of an aliquot will have to be accounted for in the case of KCl.

Facilitating Near-Infrared Persistent Luminescence in Cr3+ -Doped Gadolinium Gallium Garnets.

Near-infrared persistent luminescence (NIR PersL) materials provide great potential in the fields of night vision, biological imaging, and information encryption. However, among various crystal structures, Cr3+ -dopedgalliumgarnets show inferior PersL property, which turns out to be the bottleneck of their versatile applications. The rational design and facile preparation of high-performance NIR PersL materials are crucial for the emerging applications. In this work, a series of Gd3 Mgx Gex Ga5-2x O12 :Cr3+ (x = 0, 0.25, 0.5, 0.75, 1) is investigated by microwave-assisted solid-state (MASS) approach. Furthermore, by employing chemical composition co-substitution, PersL performance is further improved and the optimum working temperature is adjusted to the lower temperature at 10°C. Trap level distribution of Gd3 Mg0.5 Ge0.5 Ga4 O12 :Cr3+ phosphor is revealed based on the temperature and fading-time dependent PersL and thermoluminescence property. Further study demonstrates the reduction of the bandgap and the trap distribution forwards at shallow-lying trap energy levels. The synergistic effect, from both energy-band manipulation and trap-level optimization, facilitates NIR PersL in Cr3+ -doped gadolinium gallium garnets. These findings confirm the applicability of MASS-based bandgap and defect level engineering for improving the PersL properties in non/inferior-PersL materials. This burgeoning MASS method may facilitate a wide range of PersL materials for various emerging applications.

Thermoluminescent and Dosimetric Properties of Zirconium Dioxide Ceramics Irradiated with High Doses of Pulsed Electron Beam

Thermoluminescent (TL) properties of monoclinic zirconium dioxide ceramics were studied in order to assess the possibility of their use for measuring high doses (on the order of kGy) of pulsed electron beams (130 keV). Two types of samples were used: those synthesized by sintering in an electric furnace at T = 700–1700 °C and those synthesized in a flow of high-energy electrons (1.4 MeV) with a high power density. Analysis of the X-ray diffraction patterns using the Scherrer method revealed that annealing of ceramics of the first type at T > 1000 °C leads to a significant increase in the size of crystallites, which correlates with a significant increase in the intensity of the TL peak at 390 K. Type 2 ceramics synthesized by the electron beam method have the maximum TL response. Using the peak shape analysis method, the kinetic parameters of TL (activation energy, frequency factor, and kinetic order) were calculated. This study marks the first instance of establishing the patterns of influence of synthesis conditions and crystallite size on their values. The presence of an intense isolated TL peak, the sublinear nature of most dose dependencies, and negligible fading indicate the promise of the ceramics synthesized in this work for measuring high doses (several to tens of kGy).

Structural and thermoluminescence properties of magnesium oxide by exposed to beta radiation

In this research, magnesium oxide nanoparticles were produced through the chemical spray pyrolysis technique by using magnesium chloride and deionized water at room temperature. Structural characterization of magnesium oxide was carried out by x-ray diffraction system, the pattern confirmed that the prepared magnesium oxide sample has a pure MgO phase with (2 0 0) orientation. Scanning electron microscopy images (SEM) showed that the surface was covered by spherical and irregular shapes in different sizes on the nanoscale ranging between 50 nm and 100 nm. UV–Vis spectroscopy system was used to estimate the band gap energy; it was equal to 3.7 eV. In addition, we investigated the thermoluminescence and dosimetric characterization of magnesium oxide by studying the TL glow curve intensity. The results exhibited that the intensity of TL is increased with increasing of absorbed dose as a function of the temperature. According to the obtained results, MgO is a promising material as a TLD device.

Influence of Annealing Temperature on the Structural and Luminescence Features and Thermoluminescence Trap Parameters of Ca2Al2SiO7: Ce3+ Phosphors

Cerium-doped Ca2Al2SiO7 phosphors were synthesized via the combustion technique and annealed at 1073 K, 1173 K, and 1373 K. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence (PL), and thermoluminescence (TL) studies were performed to explore the variation of structural, morphological, luminescence, and TL properties with annealing temperature. The XRD plot showed an increase in crystallinity with an increase in annealing temperature. Similarly, the enhancement of PL intensity with an increase in annealing temperature supports the increased crystallinity of the phosphor samples. Detailed analysis of traps and trap parameters was carried out using the principle of TL. Samples were irradiated with different γ-ray doses, and, on heating, luminescence was observed. Thus, TL glow curves were drawn and deconvoluted using computerized glow curve deconvolution (CGCD) and Chen’s peak shape method to study the traps and trap parameters. With increasing annealing temperature, an increase in TL intensity was observed. Regardless of annealing temperature, every sample displayed a linear dose–response for doses ranging from 3 Gy to 500 Gy. TL investigations suggested that the produced phosphors are suitable candidates for gamma dosimetry applications.

Insight into the photoluminescence and thermoluminescence properties of Tb ions doping KCl crystal grown by Cz method

Insight into the photoluminescence and thermoluminescence properties of Tb ions doping KCl crystal grown by Cz method

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.

Impact of the Different Announcers of Taheri Consciousness Fields on GR-200 Dosimeters

Previously, in studies examining the effects of T-Consciousness Fields (TCFs) on the thermoluminescence properties of materials, we investigated both used and unused GR-200 dosimeters and also examined the effectiveness of TCFs on these dosimeters for approximately 21 days. The results of previous studies showed that not only do the effects of these fields persist for the duration of the study after treatment, but also, they leave a lasting impact. In this study, we made another change in the studies examining the effects of TCFs on thermoluminescence properties. TCF treatment is established through Faradarmangar’s mind or an announcer (a certified and trained individual who has been entrusted with the TCFs). By selecting a population similar to the first study (used dosimeters), we examined the response to TCFs treatments with different announcers (different individuals and genders). According to the results of this study, although the intensity and magnitude of the response have changed due to the change in the announcer, the overall trend of the response remains independent of the announcer and is consistent with the missions assigned by T-Consciousness fields, resulting in a reduction in the response.

Thermoluminescence properties of beta irradiated SrSiO3/SiO2 phosphor synthesized by hydrothermal method

This work reports on thermoluminescence (TL) of an undoped SrSiO3/SiO2 phosphor, synthesized by hydrothermal method. The crystal structures, morphology, and Thermoluminescence studies were carried out using X-ray diffraction (XRD) spectrometer, field emission scanning electron microscope (HRSEM), and TL reader respectively. The XRD patterns confirmed a mixture of both monoclinic and hexagonal phases of SrSiO3 and SiO2 phosphors respectively. SEM micrographs revealed irregular spherical nanoparticles with agglomeration. Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the presence of the elements Sr, Si and O in the SrSiO3/SiO2 phosphor. Following beta irradiation, TL measurements revealed a single broad peak at 110.5 °C which was associated to a trap having an average activation energy of 0.73 eV. A linear behaviour of dose response in a range of 0.1 Gy–1.8 kGy, the observed good reproducibility and fading supported the SrSiO3/SiO2 phosphor as a promising candidate for dosimetric applications.

Anomalous heating rate effect in GdAl3(BO3)4:Dy3+ under beta radiation stimulation: Analysis of dose response and kinetic parameters

This study presents a comprehensive investigation into the thermoluminescence (TL) properties of Dy3+-activated gadolinium aluminate garnet (Dy3+:GdAl3(BO3)4 or Dy3+-GAB) phosphor materials. The research aims to unravel the intricate interplay among heating rate, radiation dose, and TL glow curve responses to optimize dosimetry applications. The TL response of the material is scrutinized across diverse heating rates (HR) and dose levels, while accounting for temperature lag correction. Concentration quenching effects are explored through Dy3+ concentrations spanning from 0.5 to 7 wt%, revealing the optimal doping concentration to be 3 wt%. The study underscores the critical role of choosing an appropriate band-pass filter, revealing the effectiveness of the “IRSL-TL wideband blue” filter's in capturing TL signals. Furthermore, the study examines kinetic parameter estimated using different approaches and shedding light on how heating rate and radiation dose affect activation energy values. Intriguingly, the study observes an anomalous heating rate effect, resulting in elevated TL peak intensities at higher HR. This effect is attributed to non-radiative transitions and the semi-localized transition model. The reusability of Dy3+-doped GAB is also examined, confirming its consistency and reproducibility across multiple uses. This study significantly contributes to the advancement of TL dosimetry methodologies and enhances our understanding of luminescent material behaviours. We utilized both the Tm-Tstop technique in conjunction with the Initial Rise (IR) method and Computerized Glow Curve Deconvolution (CGCD) techniques, revealing the presence of seven overlapping glow peaks alongside the main ones. Both methods appear to provide excellent agreement in terms of activation energy values, ranging from 0.70 to 1.50 eV for each peak. Furthermore, the findings strongly indicate the effective utilization of TL signals in radiation dosimetry applications.

Luminescence characterizations of highly beta sensitive lithium silicate systems

The current study investigates lithium silicate systems' thermoluminescence (TL) properties. The preparation of lithium silicate systems was achieved using the solid-state reaction method. The crystal structure and the contribution of the different silicate phases to the prepared systems were propped and investigated using XRD analysis. The TL glow curves of the prepared systems were analyzed, using experimental and computational means, to determine the composing TL components and to extract their kinetic parameters. The analysis methods indicate that the glow curves are comprised of seven TL components. The results revealed that the sensitivity of the prepared systems to beta radiation is six times that of the standard TLD 100. The lower detection limit was evaluated to be 46 μGy. These promising TL properties promote the prepared lithium silicate systems to be used in many applications like radiotherapy and environmental monitoring.

Thermoluminescence properties of nano-alumina with two different particle sizes

This research aims to examine the thermoluminescence (TL) properties of nano-sized alumina, including the relationship between TL intensity and absorbed dose, the identification of individual luminescence peaks, and determining trap parameters for use as a possible dosimeter. The samples were exposed to 530 to 2646 Gy doses from 60Co irradiation. The results show that micro-sized α-Al2O3 had a main dosimetry peak at Tm = 435 K, while nano-α-Al2O3 samples with particle sizes of 40 and 50 nm displayed a TL luminescence glow curve, with the primary dosimetry peak located in the low-temperature range and a complex structure at higher temperatures (above 500 K). The primary dosimetry peak was influenced by nanoparticle size, with a maximum of 460 K for the 40 nm sample and 467 K for the 50 nm sample. The main dosimetry peak was described by the superposition of two peaks

Enhancement of thermoluminescence properties of Sr2SiO4: Eu by addition of flux for dosimetric applications

Sr2SiO4: Eu is synthesized using NaF flux by the combustion method. The synthesized product is a promising candidate for dosimetric applications. The introduction of flux allows monitoring its properties and obtaining materials with improved thermoluminescence properties. In the present work, the phosphor was characterized by X-ray diffraction, FTIR, and thermoluminescence studies. Thermoluminescence of Sr2SiO4: Eu nanophosphor prepared with and without flux has been irradiated with 60Co gamma rays and its properties are measured at room temperature. The effect of heating rate on Sr2SiO4: Eu with flux was investigated. Thus, the results reveal that the phosphors may be suitable candidates for dosimetric applications.

Synthesis, characterization and thermoluminescence properties of LiCaPO4 phosphor for ionizing radiation dosimetry

Many minerals and compounds show thermoluminescence (TL) properties but only a few of them can meet the requirements of an ideal dosimeter. Several phosphate materials have been studied for low-dose dosimetryin recent times. Among the various phosphates, ABPO4-type material shows interesting TL properties. In this study, an ABPO4-type (A = Lithium, B=Calcium) phosphor is synthesized using a modified solid-state diffusion method. Temperature is maintained below 800 °C in every step of phosphor preparation to obtain the pure phase of Lithium calcium phosphate (LiCaPO4). The purpose of this work is to synthesize LiCaPO4 using a simple method, examine its structural and luminescence properties in order to gain a deeper understanding of its TL characteristics. The general TL properties, such as TL glow curve, dose linearity, sensitivity, and fading, are investigated. Additionally, this study aims to determine various kinetic parameters through Glow Curve Deconvolution (GCD) method using the Origin Lab software together with the Chen model. XRD analysis confirmed the phase purity of the phosphor with a rhombohedral structure. Lattice parameters, unit cell volume, grain size, dislocated density, and microstrain were also calculated from XRD data. Raman analysis and Fourier Transform Infrared analysis were used to collect information about molecular bonds, vibrations, identity, and structure of the phosphor. To investigate TL properties and associated kinetic parameters, the phosphor was irradiated with 6.0 MV (photon energy) and 6.0 MeV (electron energy) from a linear accelerator for doses ranging from 0.5 Gy to 6.0 Gy. For both photon and electron energy, TL glow curves have two identical peaks near 200 °C and 240 °C.The TL glow curves for 0.5 Gy–6 Gy are deconvoluted, then fitted with the appropriate model and then calculated the kinetic parameters. Kinetic parameters such as geometric factor (μg), order of kinetics, activation energy (E), and frequency factor (s) are obtained from Chen's peak shape method. The dose against the TL intensity curve shows that the response is almost linear in the investigated dose range. For photon and electron energy, the phosphor is found to be the most sensitive at 2.0 Gy and 4.0 Gy, respectively. The phosphor shows a low fading and after 28 days of exposure, it shows a signal loss of better than 3%. The studied TL properties suggest the suitability of LiCaPO4 in radiation dosimetry and associated fields.

Photoluminescence and thermoluminescence properties of pure and rare-earth-doped ZrO2 prepared by Pechini-type sol-gel.

In this article, photoluminescence (PL) and thermoluminescence (TL) properties of ZrO2 , ZrO2 :Dy3+ , ZrO2 :Dy3+ -Gd3+ , ZrO2 :Dy3+ -Yb3+ , ZrO2 :Dy3+ -Er3+ , and ZrO2 :Dy3+ -Sm3+ phosphors synthesized by the Pechini method were investigated. The crystal structure, thermal properties, morphology, PL and TL properties were investigated using X-ray powder diffraction (XRD), differential thermal analysis/thermogravimetric analysis (DTA/TGA), scanning electron microscopy (SEM), PL and TL, respectively. The room temperature emission bands corresponding to 4 F9/2 →6 HJ (J= 9/2, 11/2, 13/2 and 15/2) transitions of Dy3+ ions were measured. The phosphors were analysed using Tm -TSTOP , variable dose, and computerized glow curve fitting methods. Reusability, dose-response, and fading characteristics were investigated. The phosphors have a natural TL emission that vanished by heating treatment. Moreover, new peaks with similar properties to the natural emissions were observed after high-dose irradiation and long-term fading experiments. The glow curves of the phosphors have 13 individual peaks and many low- and high-temperature satellite peaks. The origin of the peaks is ZrO2 host material and doping with rare-earth ions (Gd3+ , Dy3+ , Yb3+ , Er3+ and Sm3+ ) does not lead to a new glow peak. The dopants cause drastic changes in individual peak intensities of ZrO2 .The initial fading rates of all the phosphors are relatively fast, but they slow down as time goes on.

Assessment of structural and thermoluminescence characteristics of porcelain used as an electrical insulator

AbstractIn the present work, the thermoluminescence (TL) properties and kinetics of beta‐irradiated porcelain used as an electrical insulator are investigated in great depth. Thermal annealing at 1100°C slightly changes the trap system, whereas heating over 500°C increases the visual TL intensity of the peaks. X‐ray diffraction, scanning electron microscopy with energy dispersive X‐ray spectroscopy, atomic absorption spectroscopy, and Fourier transform infrared spectroscopy were used to confirm the structural, morphological, and chemical investigations of the materials. The TL glow curve characteristics, repeatability, storage time properties, and dose–response behavior of non‐annealed and annealed porcelain have all been well investigated. Within the confidence interval, the material has been demonstrated to have excellent reusability. A linear response in the dose range of 0.1–3 Gy was observed. TM–Ts, initial rise, and computerized glow curve deconvolution methodologies were used to complete the kinetic study. The outcomes of the detailed investigations demonstrated that the sample was suitable for TL dosimetry potential uses.

The influence of Dy3+ ions on physical, structural, optical, and thermoluminescence characteristics of Li2O – BaO – B2O3 – P2O5 glass system

Dy3+-activated glasses with composition 15Li2O - 25BaO - (40-x)B2O3 – 20P2O5 – xDy2O3, where x = 0, 0.2, 0.4, 0.6, 0.8, and 1.0 mol%, were synthesised using melt quenching technique for studying their physical, structural, optical, and thermoluminescence properties. The physical attributes were assessed using density and molar volume values. X-ray diffraction proved amorphous nature of glasses while Fourier transform infrared spectroscopy revealed the presence of structural groups. Optical absorption spectra with wavelengths spanning from 300 to 1200 nm were used to examine different optical properties. With an aim to study dosimetric properties, the glasses were irradiated with various gamma doses (50 Gy to 10 kGy). Chen's peak shape approach was used to establish kinetic parameters of glow curves in 325–500 K temperature range. The results suggest that due to high thermoluminescence efficiency, the glass sample with 0.8 mol% of Dy3+ concentration is best suitable for the dosimetric applications.

Thermoluminescence studies of NaMgF3:Tb for gamma dosimetry applications

NaMgF3 is a recognized sensitive thermoluminescence (TL) dosimeter but it shows fading at room temperature which limits its use as a radiation dosimeter. It is important to improve this parameter of NaMgF3 for its potential application in the field of radiation dosimetry. Thus, the current work focuses on enhancing the dosimetric properties of NaMgF3 exclusively the TL fading characteristics. In the present study, Tb doped NaMgF3 has been synthesized by two different methods i.e. solid state reaction method (SSR) and melting method (MT). A comparative and detailed TL studies have been carried out after irradiation with gamma rays which has not been reported so far. Detailed analysis of TL and Photoluminescence (PL) properties reveal that NaMgF3:Tb prepared via MT shows good luminescence properties in comparison to SSR and previously reported results. Thus, Tb doped NaMgF3 synthesized by melting method can be a potential dosimeter for the detection of gamma rays.

Thermoluminescence dosimeter (TLD) studies of Ca10 K(PO4 )7 :Dy phosphor for applications in radiation dosimetry.

This study reports the thermoluminescence (TL) aspects of Ca10 K(PO4 )7 :Dy phosphor synthesized using a wet chemical method for the first time. The X-ray diffraction (XRD) results confirm the formation of the desired crystalline phase. Surface morphological studies reveal the formation of polyhedrons and agglomerations having an average diameter of 200 nm, while energy dispersive X-ray spectroscopy (EDS) data show the presence and composition of the elements in appropriate amounts. The effect of Dy doping concentration has been studied on the TL properties with exposure to gamma radiations from the Co-60 source. The best TL response has been observed for 5mol% Dy doping concentration. The glow curve is simple and consists of a single peak at 130°C. The effect of the heating rate has been studied on the TL glow curve, and the heating rate of 5°C/s shows the best TL response. The various TL properties such as annealing conditions, dose-response, TL linearity, fading, and reusability of the prepared phosphor have been studied to check its suitability as a good TL dosimeter (TLD). TL characterization of the phosphor reports that the TL response is linear from 5- to 2000 Gy. The results show that this phosphor can be a good TLD for the dosimetry of gamma radiations from Co-60.

Study on the thermoluminescence and optically stimulated luminescence of LiMgPO4:Dy phosphors synthesized by different methods

LiMgPO4:Dy phosphors were synthesized by high-temperature solid-state method and sol-gel method. The effects of different synthesis methods on crystal structure, morphology, thermoluminescence (TL) properties, and optically stimulated luminescence (OSL) properties of LiMgPO4:Dy were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), TL glow curve and continuous wave OSL (CW-OSL) curves. XRD patterns showed that the crystal phase of the samples synthesized by the two methods is LiMgPO4. The morphology of the samples synthesized by sol-gel method was better than that synthesized by high-temperature solid-state method. The TL sensitivity of the samples synthesized by sol-gel method was higher than that synthesized by high-temperature solid-state method. The TL strongest glow peak of the LiMgPO4:Dy sample synthesized by high-temperature solid-state method was 363 K, while that the LiMgPO4:Dy sample synthesized by sol-gel method was 380 K. The OSL sensitivity of the samples synthesized by sol-gel method was significantly higher than that synthesized by high-temperature solid-state method. The synthesis method had no effect on the OSL decay of the sample. LiMgPO4:Dy phosphor synthesized by sol-gel method may be a suitable candidate material for radiation dosimetry.