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Öğe Beta irradiation-induced thermoluminescence: Glow curve analysis and kinetic parameters in combustion-synthesized undoped Ca4YO(BO3)3(Pergamon-Elsevier Science Ltd, 2024) Madkhli, A. Y.; Jabali, D. A.; Souadi, G.; Sonsuz, M.; Kaynar, U. H.; Akca-Ozalp, S.; Ayvacikli, M.This study examines the thermoluminescent (TL) properties of undoped Ca4YO(BO3)3 phosphor, focusing on how it behaves under a variety of experimental conditions. The IRSL-TL 565 nm was chosen as the appropriate detection filter among various optical detection filter combinations. During the preheating trials conducted at a rate of 2 degrees C/s, the TL peak exhibited increased intensity, particularly around 200 degrees C. The experimental outcomes demonstrated a reliable linear relationship (R2 = 0.996 and b = 1.015) in the dose response of undoped preheated Ca4YO(BO3)3 within the range of 1-200 Gy. The investigation encompasses a range of techniques, including the TM-Tstop method, computerized glow curve deconvolution (CGCD) analysis, and theoretical modelling. The application of the TM-Tstop method to samples irradiated with a 5 Gy dose revealed distinct zones on the TM versus Tstop diagram, signifying the presence of at least two discernible components within the TL glow curve, specifically, a single general order kinetics peak and a continuous distribution. The analysis of activation energy versus preheated temperature exhibited a stepwise curve, indicating five trap levels with depths ranging between 1.13 eV and 1.40 eV. The CGCD method also revealed the superposition of at least five distinct TL glow peaks. It was observed that their activation energies were consistent with the Tm-Tstop experiment. Furthermore, the low Figure of Merit (FOM) value of 1.18% indicates high reliability in the goodness-of-fit measure. These findings affirm the reliability and effectiveness of the employed methods in characterizing the TL properties of the Ca4YO(BO3)3 phosphor under investigation. Theoretical models, including the semi-localized transition model, were introduced to explain anomalous observations in TL glow peak intensities and heating rate patterns. While providing a conceptual framework, these models may require adjustments to accurately capture the specific characteristics uncovered through CGCD analysis. As a potential application, the study suggests that the characterized TL properties of Ca4YO(BO3)3 phosphor could be utilized in dosimetric applications, such as radiation dose measurements, owing to its reliable linear response within a broad dose range.Öğe Samarium doped Ca(3)Y2B(4)O(12) phosphor prepared by combustion method: Anomalous heating rate effect, dosimetric features, and TL kinetic analyses(Elsevier, 2022) Hakami, J.; Oglakci, M.; Portakal-Ucar, Z. G.; Sonsuz, M.; Kaynar, U. H.; Ayvacikli, M.; Topaksu, M.The structural and thermoluminescence characteristics of samarium doped Ca3Y2B4O12 samples at various concentrations are presented. The samples were synthesized via the combustion method. The thermolumines-cence (TL) glow curves for Ca(3)Y2B(4)O(12):Sm3+ depict strong peaks at 97 and 410 C. Ca(3)Y2B(4)O(12):Sm3+ exhibited completely opposite behavior, contrary to expectations, in that the luminescence intensity of both the total and individual glow peaks increased with the heating rate throughout the TL experiments. This unusual TL glow peak pattern was discussed via the Mandowski model of semi-localized transitions. The kinetic characteristics of both prominent glow peaks were established using various analysis techniques, including variable heating rate, initial rise (IR) by using the TM-Tstop method and the fractional glow technique (FGT), and computerized glow curve deconvolution (GCD). The dose response of the high temperature peak at 410 C is linear between 0.1 and 5 Gy, and then sublinear at higher doses. In addition, the repeatability and fading results of 410 C TL peak also yielded very favorable results. These findings suggest that Ca(3)Y2B(4)O(12):Sm(3+ )has great potential in the development of high temperature dosimetric materials for beta irradiation.Öğe Synthesis and thermoluminescence behavior of novel Sm3+ doped YCa4O(BO3)3 under beta irradiation(Elsevier Sci Ltd, 2024) Altowyan, Abeer S.; Sonsuz, M.; Kaynar, U. H.; Hakami, Jabir; Portakal-Ucar, Z. G.; Ayvacikli, M.; Topaksu, M.This study investigates the luminescent properties and dosimetric potential of YCa 4 O(BO 3 ) 3 :0.5%Sm 3+ phosphor synthesized via the combustion method. Dose -response investigations unveil a noteworthy linear increment in thermoluminescence (TL) intensity, emphasizing a remarkable linearity spanning a broad dose range from 0.1 to 300 Gy. Unusual heating rate effects are explored, revealing a shift in TL glow curve peak temperature (i.e 200 degrees C) towards higher temperatures with increasing heating rate. Speculative models, including Kinetic Trapping Effect, Thermal Quenching Compensation, and Defect Activation Energy Changes, are proposed. The study employs the T max - T stop method to identify characterize glow curve peaks, and the Initial Rise method for the lowtemperature segment analysis, revealing seven distinct trap levels at various depths within the bandgap. Glow curve deconvolution using the Complex Glow Curve Deconvolution (CGCD) method delineates a multi -peak structure, offering valuable insights into luminescent mechanisms. The model exhibits a Figure of Merit (FOM) of 1.71%, within an acceptable range, affirming its reliability. However, interpretation of the activation energy and frequency factor values suggests intricate site processes, necessitating a nuanced analysis to understand the material 's luminescent characteristics. The YCa 4 O(BO 3 ) 3 :0.5%Sm 3+ phosphor demonstrates promising characteristics for precise dosimetry, with linear dose response, absence of saturation effects, and intriguing heating rate behavior.Öğe Thermoluminescence characteristics of a novel Li2MoO4 phosphor: Heating rate, dose response and kinetic parameters(Pergamon-Elsevier Science Ltd, 2022) Souadi, G.; Kaynar, Ümit. Hüseyin; Oğlakçı, M.; Sonsuz, M.; Ayvacıklı, M.; Topaksu, M.; Canımoğlu, A.Lithium molybdate (Li2MoO4) phosphor was synthesized by a gel combustion method and its thermoluminescence properties were studied with the irradiation of beta. Various Heating Rate (VHR), Initial Rise (IR), and Computerized Glow Curve Deconvolution (CGCD) methods were used to determine the kinetic parameters (activation energy E (eV), frequency factor s (s(-1)), and kinetic order b) of the visible glow peaks. According to the kinetic study, the TL glow curve is made up of seven separate peaks with activation energies of 1.05, 0.76, 0.40, 0.60, 0.78, 1.81 and 1.25 eV and these peaks follow general-order kinetics. The results clearly showed that undoped Li2MoO4 has a potential to be considered in dosimetric applications where high doses have to be monitored as in the case of clinical dosimetry.Öğe Thermoluminescence characterization and kinetic parameters of Dy3+ activated Ca3Y2B4O12(Elsevier, 2022) Hakami, J.; Sonsuz, M.; Kaynar, Ümit Hüseyin; Ayvacikli, M.; Oğlakçı, Mehmet; Topaksu, M.; Can, N.In this study, thermoluminescence (TL) characteristics of Ca3Y2B4O12:xDy (0 < x < 0.07) phosphor samples were studied. The samples were exposed to beta irradiation in the dose range from 0.1 Gy to 100 Gy to investigate TL dose response. The concentration of Dy3+ in Ca3Y2B4O12 phosphor was optimized and found to be 1 mass % in terms of TL signal quality. The TL glow curve appears to be consisted of three peaks which were discernible at 72 degrees C, 280 C and 376 degrees C. The trapping parameters (E, b, and s) were calculated using initial rise (IR), and variable heating rate (VHR) techniques. The trapping parameters, order of kinetics, frequency factor, and figure of merit have been all determined by means of the Glow Curve Deconvolution (GCD) method (tgcd:An R package). Ca3Y2B4O12:Dy phosphor displays efficient thermoluminescence properties.Öğe Thermoluminescence glow curve analysis of Ca3Y2B4O12 phosphor prepared using combustion method(Pergamon-Elsevier Science Ltd, 2022) Hakami, J.; Sonsuz, M.; Kaynar, U. H.; Ayvacikli, M.; Oglakci, M.; Yueksel, M.; Topaksu, M.Ca3Y2B4O12 (CBYO) phosphor was synthesized using a gel combustion method. X-ray diffraction (XRD) measurement confirmed a single-phase structure (space group Pnma (62)) of synthesized compound. TL measurements were conducted between room temperature (RT) and 450 degrees C at a heating rate of 2 degrees Cs-1. Significant glow peaks were observed at 64, 116, and 242 degrees C in CYBO phosphor sample exposed to different beta doses. In the range of 0.1-100 Gy, the TL intensity of the glow peak displayed good linearity. Different methods were employed to determine the number of peaks, the trap structure, and the kinetic parameters of the thermoluminescence glow curve of CBYO; the Hoogenstraaten method, various heating rates (VHR), and glow curve deconvolution method (CGCD) implemented through tgcd:An R package. Currently available findings confirm that CYBO host is a promising candidate for environmental studies because one exhibits adequate TL dose response coupled with a good sensitivity and linearity.Öğe Thermoluminescence in GdAl3(BO3)4 phosphors: Unusual heating rate dependencies, dose responses and kinetic parameters(Pergamon-Elsevier Science Ltd, 2023) Alajlani, Y.; Sonsuz, M.; Barad, A.; Kaynar, Uemit H.; Ayvacikli, M.; Topaksu, M.; Can, N.The current study focuses on the production of GdAl3(BO3)4 (GAB) phosphors using gel combustion. X-ray diffraction (XRD) and thermoluminescent (TL) methods were used to investigate the structural and thermolu-minescence (TL) features of the samples. XRD results revealed that GAB phosphors were crystallized in a rhombohedral crystal system. TL experimental data exhibited an unusual heating rate behaviour, which was explained by the semi-localized transition model, and this provides valuable insight into the properties of the GAB sample. Beta-irradiated GAB hosts exhibit two primary peaks at 106 degrees C and 277 degrees C on their TL glow curves. We have employed a variety of heating rates (VHRs), TM-Tstop method, and computerized glow curve decon-volution (CGCD) techniques. By using a combination of these techniques, we can identify the kinetic parameters of the GAB samples more accurately, including peak numbers, activation energy, and frequency factors. Both Tm- Tstop and CGCD techniques produce similar results in terms of trap numbers and trap depths. In the trap centers, electrons were trapped at 1.05 eV, 0.84 eV, 1.12 eV, 1.20 eV, 1.42 eV, 1.63 eV and 1.42 eV. There was a linear behaviour of GAB samples over a dose range of 0.1 Gy-10 Gy. GAB phosphors did not show any significant changes in TL response with repeated irradiation cycles, suggesting that it is a reliable radiation dosimeter. GAB is therefore a potential candidate for radiotherapy dose measurement based on these findings.Öğe Thermoluminescence kinetic parameters of beta irradiated the zinc gallate phosphor using different methods(Elsevier Sci Ltd, 2023) Altowyan, Abeer S.; Sonsuz, M.; Kaynar, Umit H.; Hakami, Jabir; Ayvacikli, M.; Topaksu, M.; Can, N.The ZnGa2O4 phosphor material was synthesised through the gel combustion method, and its structural characteristics were studied via X-ray powder diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). The XRD result indicates the generation of ZnGa2O4 in spinal cubic phase with a 25 nm crystalline size. The synthesized phosphor was irradiated using a90Sr/90Y source with a dose range of 0.1 Gy-100 Gy. For measuring thermoluminescence (TL), a linear heating rate of 2 degrees Cs ? 1 was applied to the sample in a temperature range of 25 degrees C-450 degrees C. The TL experiment revealed two peak maxima located at 180 degrees C and 304 degrees C and a shoulder around 70 degrees C. By preheating at 110 degrees C, the low temperature peak at 70 degrees C is removed. Both the depth and frequency factors of electron traps were determined using various heating rates (VHR), Tm-Tstop combined with initial rise (IR), and Computerised Glow Curve Deconvolution (CGCD). In both the Tm-Tstop and CGCD methods, six overlapping glow peaks were detected below the main glow peaks. The calculated activation energy values and peak maximum temperatures agree well with each other. The depths of electron traps calculated by different methods were found to be between 0.4 and 1.4 eV. We observed that both peak maximum temperatures and the area under glow peaks gradually decreased with an increase in the heating rate. Both Peak 1 and Peak 2 show sublinear relationship between 0.1-5Gy and 10-100 Gy. The findings of the present study show that the phosphors can serve as effective TLDs.Öğe Unravelling the impact of unusual heating rate, dose-response and trap parameters on the thermoluminescence of Sm3+activated GdAl3(BO3)4 phosphors exposed to beta particle irradiation(Pergamon-Elsevier Science Ltd, 2023) Souadi, G.; Kaynar, Umit H.; Sonsuz, M.; Akca-Ozalp, S.; Ayvacikli, M.; Topaksu, M.; Ozmen, O. T.The thermoluminescence of GdAl3(BO3)4 (GAB) doped with various concentrations of Sm3+ (i.e. from 0.5 to 7 wt %), prepared by gel combustion, was studied. TL glow peaks at 78 degrees C and 225 degrees C are observed. The intensity of the glow peak at 225 degrees C increased with a faster heating rate. To gain insight into the trap activation energies, the methods of Hoogenstraaten and Booth-Bohun-Parfianovitch were used, where the calculated activation energies are 0.57 eV and 0.60 eV for Peak I and 1.69 eV and 1.71 eV for Peak II respectively. The dose-response of GAB:0.5 wt%Sm3+ demonstrates robust linearity up to 40 Gy, with a strong correlation coefficient of 0.999. Both TM-Tstop combined with the Initial Rise (IR) and Computerized Glow Curve Deconvolution (CGCD) techniques were employed, which revealed six overlapping glow peaks beneath the main peaks. Additionally, the results suggest that the TL signal can be efficiently exploited for radiation dosimetry applications.
