Browsing by Author "Hiziroglu A."

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    Thermoluminescence glow curve analysis and kinetic parameters of Eu doped Li2MoO4 ceramic phosphors
    (Elsevier Ltd, 2022) Souadi G.; Oglakci M.; Kaynar U.H.; Correcher V.; Benavente J.F.; Bulcar K.; Ayvacikli M.; Hiziroglu A.; Topaksu M.; Can N.; Karali E.E.
    LiMoO4: x Eu ceramic phosphors with x = 0.5, 1, 2, 3, 5, and 7 mol% were synthesized using a gel combustion method. X-ray diffraction (XRD) measurements confirmed a rhombohedral structure (space group R3) of synthesized compounds. Following irradiation with 50 Gy beta dose, the sample doped with 5 mol% Eu exhibited the highest integrated thermoluminescence (TL) intensity. In order to evaluate dose-response, samples were irradiated with beta radiation for 10–1000 Gy. TL intensity with 1000 Gy dose without saturation yielded the highest integrated value. Different methods were employed to determine the number of peaks, the trap structure, and the kinetic parameters of the thermoluminescence glow curve of Eu doped Li2MoO4: the Hoogenstraaten method, the Booth-Bohun-Parfianovitch method, the initial rise method (IR), combined with the TM-Tstop experiment, various heating rates (VHR), and glow curve fitting with two different software packages. Based on the glow curve deconvolution obtained using both software packages, the component TL glow peaks present in the complex glow curve are composed of well-isolated nine overlapping glow peaks. Two software packages have shown quite similar activation energies and frequency factors. © 2022 Elsevier Ltd and Techna Group S.r.l.
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    Temperature-dependent photoluminescence of novel Eu3+, Tb3+, and Dy3+ doped LaCa4O(BO3)3: Insights at low and room temperatures
    (Elsevier Ltd, 2024) Altowyan A.S.; Coban M.B.; Kaynar U.H.; Hakami J.; Ayvacikli M.; Hiziroglu A.; Can N.
    This study explores the structural and optical qualities of LaCa4O(BO3)3 (LACOB) phosphors doped with Eu3+, Dy3+, and Tb3+ using a microwave-assisted sol-gel technique. It uncovers oxygen-related luminescence defects in LACOB, highlighting emission peaks at 489 and 585 nm for Dy3+, a distinct sharp peak at 611 nm for Eu3+ in the red spectrum, and a notable green emission for Tb3+ due to specific transitions. The photoluminescence (PL) analysis indicates that luminescence is optimized through precise doping, leveraging dipole interactions, and localized resonant energy transfer, which are influenced by dopant concentration and spatial configuration. Temperature studies show emission intensity variations, particularly noticeable below 100 K for Tb3+ doped samples, demonstrating the nuanced balance between thermal quenching and luminescence efficiency. This temperature dependency, alongside the identified optimal doping conditions, underscores the potential of these materials for advanced photonic applications, offering insights into their thermal behavior and emission mechanisms under different conditions. © 2024 Elsevier Ltd