Browsing by Author "Eren Cihan Karsu Asal"

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    Amazonite in Pakistan: A Comprehensive Study with XRD, XPS, SEM, and PL Analyses
    (2023) Eren Cihan Karsu Asal
    Although amazonite minerals from various locations have been studied before rather less attention has been paid to the amazonite mineral from Pakistan. The present work is presented an extensive structural characterization of natural amazonite aliquots (KAlSi3O8) from Tangir Valley, Gilgit-Pakistan. The phase and elemental analysis have been characterized by both X-ray Diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS), respectively. The surface morphology and particle size have been identified by Scanning Electron Microscopy (SEM). The luminescence properties have been investigated using PhotoLuminescence (PL). In addition, the lifetime of the PL emission measurements has been estimated. Eventually, this microcline has a triclinic phase, mainly composed of (AlO4)-5 ions, SiO2, metal SiO4, Al2O3 and oxygen originating from impurities. The average particle size is around 1–10 µm with a complex structure. The PL spectrum has broad emission and excitation bands (520 nm and 340 mm respectively). The average lifetime of the PL emission is 265,21 µs. For the accuracy of the results all experiments were performed with not only a single aliquot, but with three aliquots, and representative results are presented.
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    Orange Emitting SrS: Eu2+, Dy3+ Afterglow Phosphor: Structural and Luminescence Properties
    (2024) Eren Cihan Karsu Asal; Serdar YILDIRIM
    SrS:Eu is known as an attractive material for imaging, scintillator, or persistent phosphor applications, thanks to its effective photoluminescence (PL) and thermoluminescence (TL) capabilities, but there are still great mysteries of persistent phosphors and attract great interest. Hence, this work investigated the luminescence properties of well-known persistent phosphor based on SrS using various spectroscopic techniques for detailed characterization. Measurements using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were used to analyze the phase and elements of the phosphor. Belongs to the XRD data the microcrystalline phosphor is cubic, and the diameters ranged from 1 to 100 µm. The morphology of the phosphor was examined by scanning electron microscope (SEM). A time-resolved PL system recorded PL properties, namely the emission and excitation spectra of the phosphor. SrS emits around 626 nm with a broad excitation band peaking around 466 nm. A TLD reader system measured the TL glow curve of the phosphors after UVB radiation. The TL glow curve exhibited a broad peak around 160oC. The dose-response of this peak was obtained up to 600 seconds of exposure to UVB radiation, and it was observed that the dose-response curve exhibits a saturating exponential behavior.