Yazar "Maleque, M. A." seçeneğine göre listele

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    Öğe
    Optical and structural characterization of (Mn, Fe) co-doped lead chalcogenides for optoelectronics applications
    (Natl Inst Optoelectronics, 2021) Merabet, B.; Ozkendir, O. M.; Hassanien, A. S.; Maleque, M. A.
    Lead chalcogenides (LCs) exhibit non-stability and lower device efficiency due to smaller bandgap (E-g) leading to poor optical properties for photovoltaic (PV) applications. In this work, optical properties of transition metals (TMs) such as (Mn and Fe) co-doped with LCs especially PbS in the framework of DFT+U (8 eV) and L/APW+/o method are theoretically investigated to predict new optical material for photovoltaic and other optoelectronics applications. The XAFS spectroscopy technique was used to analyze electronic structures and optical properties of (Mn, Fe) co-doped LCs. Midgap states of co-doped PbS reveal to improve the absorption of infrared light mainly due to slight doping with TMs. Compared to pure PbS, Mn doping in PbS induces E-g widening, blue-shift, and improve the light absorption edge. Due to co-doping, the magnetic order is translated that can lead to forming a charge compensated system which is beneficial to minimize vacancies related to defects formation.
  • [ X ]
    Öğe
    Spin-orbit coupling effect on the electronic structure of Sr2FeHfO6 alloy for spintronics application
    (Elsevier, 2021) Merabet, B.; Ozkendir, O. M.; Hassanien, A. S.; Maleque, M. A.
    Strong spin-orbit coupling (SOC) in Sr2FeHfO6 (SFHO) alloy has been predicted by means of full-potential linear augmented plane wave method in order to study the effect on electronic structure. The tetragonal (I4/mmm) SFHO with SOC has an up-spin energy of similar to 1.2 eV and a total magnetic moment of similar to 2.03 mu B mainly coming from the Fe (1.63 mu B), and the SOC effect was prominent in SFHO due to the magnetic moment of 3d-Fe orbitals. The XAFS spectroscopy technique was used in order to analyze the electronic structure and optical properties of SFHO. The absorption spectra with Fe as a source atom shows a peak appearing around 7118 eV. SFHO with SOC falls within the half metallic state in the up-spin direction resulting significant increase of the total magnetic moment. This half-metallicity strong SOC in SFHO demonstrate much spin polarized electrons around the Fermi level, hence, this material is very potential in future memory devices and spintronic applications.