Browsing by Author "Hammoudeh A."

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    Synthesis and competitive luminescence quenching mechanism of Ca3Al2O6:Ln3+ (Ln: Dy and Sm) phosphors
    (Elsevier Ltd, 2020) Bakr M.; Kaynar Ü.H.; Ayvacikli M.; Benourdja S.; Karabulut Y.; Hammoudeh A.; Can N.
    Sm3+ and Dy3+ activated Ca3Al2O6 phosphors were produced through a gel combustion method using Urea + β-Alanine, Urea, and Urea + Glycine as fuels. The crystal structure and the phase purity of the obtained materials were characterized by X-ray powder diffraction (XRD). Ca3Al2O6:Sm3+ phosphor shows characteristic emission lines (565 nm, 602 nm, 649 nm, and 714 nm) in the orange red region assigned to 4G5/2→6HJ (J = 5/2, 7/2, 9/2, 11/2) transitions of Sm3+. The strongest peak is located at 602 nm. Emission spectra of Ca3Al2O6:Dy3+ show that there are two dominant peaks centered at 480 nm and 573 nm emitting blue and yellow light. Optimum doping concentrations of Sm(NO3)3 and Dy(NO3)3 are 0.01 % and 0.03 %, respectively. The concentration quenching mechanism is verified to be a dipole-dipole interaction as the type of energy transfer among Sm3+-Sm3+ and Dy3+-Dy3+ ions. The critical distance is also calculated to be 24.19 Å and 16.77 Å, respectively. © 2020 Elsevier Ltd
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    Thermoluminescence properties of beta particle irradiated Ca3Al2O6 phosphor relative to environmental dosimetry
    (Elsevier B.V., 2020) Bakr M.; Portakal-Uçar Z.G.; Yüksel M.; Kaynar Ü.H.; Ayvacikli M.; Benourdja S.; Canimoglu A.; Topaksu M.; Hammoudeh A.; Can N.
    Undoped Ca3Al2O6 phosphor was successfully synthesized through a gel-combustion method using different fuels. It was characterized by X-ray diffraction (XRD) technique and its cubic phase structure was confirmed from XRD pattern. TL data were recorded from room temperature (RT) to 500 °C in the heating rate of 2 °C/s. The glow curves of Ca3Al2O6 sample exposed to different beta doses (0–200 Gy) exhibited a significant glow peak at about 184 °C. The TL intensity of the glow peak exhibited very good linearity between 0.1 and 10 Gy. Following this, it was decreased at higher doses which was referred to this effect as monotonic dose dependence. Initial rise (IR), peak shape (PS), and variable heating rate (VHR) methods were used to estimate trapping parameters. Computerized glow curve deconvolution (CGCD) method via TLAnal software was also applied to estimate the number of peaks and kinetic parameters corresponding to the main glow curve in Ca3Al2O6 sample. The trapping activation energy of the main dosimetric peak was calculated to be around 1.30 eV for all methods. Present findings confirm that Ca3Al2O6 host is a promising candidate for applications in environmental dosimetry as one depicts good TL dose response with adequate sensitivity and linearity. © 2020 Elsevier B.V.