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Öğe Beta-irradiated ZnGa2O4:Sm3+phosphor: Thermoluminescence glow curves and kinetic parameters via gel combustion synthesis(Elsevier Science Sa, 2024) Barad, A.; Topaksu, M.; Hakami, J.; Kaynar, U. H.; Akca-Ozalp, S.; Altowyan, Abeer S.; Aydin, H.This study examines the X-ray Diffraction (XRD) characteristics of Sm 3+-doped ZnGa 2 O 4 phosphor, shedding light on its structural characteristics. The XRD data reveal distinctive peaks that represent the crystal 's lattice structure. This provides the basis for a more detailed analysis of thermoluminescence (TL). Initially, the TL glow curves corresponding to different concentrations of Sm were analysed, leading to the identification of the most favorable Sm concentration. Subsequently, an investigation was conducted into the TL behavior of the material in response to varying doses within a broad spectrum of beta radiation, revealing a linear characteristic (b=1.075) across doses ranging from 0.1 Gy to 50 Gy. Following this, a reusability assessment was executed over three measurement sets, wherein it was ascertained that the deviation in peak area across ten cycles did not surpass 2 %. Furthermore, it was investigated how different heating rates ranging from 0.5 degrees C/s to 7 degrees C/s affect the TL curve of the material. To determine the TL trap parameters of the sample, Initial Rise (IR) and Computerized Glow Curve Deconvolution (CGCD) methods were employed. A consistent pattern of activation energy values was observed in both IR in the T M-T stop experiment and CGCD analyses, indicating a uniform response to distinct energy levels within the sample. In terms of providing valuable insights into the characteristics of TL, these methods were found to be very effective. This contributed to a comprehensive understanding of charge carrier dynamics within the crystal lattice. Moreover, Peaks I, II, and III showed a linear response to applied doses, indicating the material 's potential for dosimetry applications. The findings of this study not only provide insights into Sm 3+-doped ZnGd 2 O 4 phosphors ' TL properties, but also enhance our understanding of how to optimize their radiation response.Öğe Enhancement of luminescence and thermal stability in Eu3+-doped K3Y (BO2)6 with Li+ and Na+ co-doping(Elsevier, 2024) Kaynar, U. H.; Aydin, H.; Altowyan, A. S.; Hakami, J.; Coban, M. B.; Ayvacikli, M.; Karali, E. EkdalEu3+-doped and Li+/Na+ co-doped K3Y(BO2)6 (KYBO) phosphors were synthesized through a microwave- assisted sol-gel method, and their structural and photoluminescent (PL) characteristics were examined. X-ray diffraction (XRD) and Rietveld refinement confirm effective dopant incorporation and preservation of the crystalline structure. Fourier Transform Infrared (FTIR) spectroscopy indicates the maintenance of the borate structure, confirming the structural integrity of the phosphors upon doping. The addition of Li+ and Na+ co-dopants notably enhances luminescent efficiency and thermal stability, making these phosphors promising candidates for solid-state lighting (SSL) applications. PL analysis reveals strong red emission peaks at 612 nm, attributed to the 5 D o ? 7 F 2 transition of Eu3+ ions. The study indicates that electric dipole-quadrupole interactions are the primary mechanism for energy migration, with a critical distance of approximately 22.68 & Aring;. This mechanism contributes to concentration quenching at higher doping levels. High temperature PL measurements indicated an activation energy of 0.1389 eV for thermal quenching in the Li+ co-doped sample. Additionally, the Na+ co-doped sample exhibited an abnormal thermal stability behavior, with an even higher activation energy of 0.2536 eV. This suggests that Na+ co-doping significantly enhances the thermal resilience of the phosphor, making it more suitable for high-power light-emitting applications that operate under extreme conditions. CIE chromaticity diagrams highlight the potential for optimizing Eu3+ doping levels, combined with Li+ and Na+ co-doping, to improve luminescent performance and thermal stability for advanced SSL applications. (c) 2024 The Society of Powder Technology Japan. Published by Elsevier BV and The Society of Powder Technology Japan. All rights are reserved, including those for text and data mining, AI training, and similar technologies.Öğe Enhancement of luminescence and thermal stability in Eu3+-doped K3Y(BO2)6 with Li+ and Na+ co-doping (vol 35, 104695, 2024)(Elsevier, 2024) Kaynar, U. H.; Aydin, H.; Altowyan, Abeer S.; Hakami, J.; Coban, M. B.; Ayvacikli, M.; Karali, E. Ekdal[No abstract available]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 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.
