Yazar "Mamedov, Amirullah M." seçeneğine göre listele

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  • Küçük Resim
    Öğe
    First principles prediction of the elastic, electronic, and optical properties of Sb2S3 and Sb2Se3 compounds
    (Elsevier, 2012) Koç, Hüsnü; Mamedov, Amirullah M.; Deligöz, Engin; Özışık, Hacı
    We have performed a first principles study of structural, mechanical, electronic, and optical properties of orthorhombic Sb 2S 3 and Sb 2Se 3 compounds using the density functional theory within the local density approximation. The lattice parameters, bulk modulus, and its pressure derivatives of these compounds have been obtained. The second-order elastic constants have been calculated, and the other related quantities such as the Young's modulus, shear modulus, Poisson's ratio, anisotropy factor, sound velocities, Debye temperature, and hardness have also been estimated in the present work. The linear photon-energy dependent dielectric functions and some optical properties such as the energy-loss function, the effective number of valence electrons and the effective optical dielectric constant are calculated. Our structural estimation and some other results are in agreement with the available experimental and theoretical data.
  • [ X ]
    Öğe
    Optical and magnetic properties of some XMnSb and Co(2)YZ Compounds: ab initio calculations
    (WILEY-V C H VERLAG GMBH, 2017) Palaz, Selami; Koç, Hüsnü; Özışık, Hacı; Deligöz, Engin; Mamedov, Amirullah M.; Özbay, Ekmel; Maiberg, M; Franzel, W; Scheer, R
    In present work, our research is mainly focused on the electronic structures, optical, and magnetic properties of XMnSb (X = Ni, Cu, Pd), Co(2)YZ (Y = Ti; Z = Si, Ge, Sn), and Co(2)YZ (Y = Mn; Z = Al, Ga, Si) Heusler compounds by using ab initio calculations within the generalized gradient approximation. The calculations are performed by using the Vienna ab initio simulation package based on the density functional theory. The band structure of these Heusler alloys for majority spin and minority spin were calculated and the majority spin states cross the Fermi level and thus have the metallic character, while the minority spin states open the band gaps around the Fermi level and thus have the narrow-band semiconducting nature. We also find that these Heuslercompounds have the indirect band gaps in the minority spin channel. The real and imaginary parts of dielectric functions and hence the optical functions such as energy-loss function, the effective number of valance electrons and the effective optical dielectric constant for XMnSb and Co2YZ compounds were also calculated. In addition, we also show the variations of the total magnetic moment per f.u. and minority spin gap width of these compounds with optimized lattice constants: minority spin gap width decreases with increasing the lattice constants.
  • Küçük Resim
    Öğe
    The elastic, electronic, and optical properties of PtSi and PtGe compounds
    (Taylor & Francis Ltd, 2011) Koç, H.; Deligöz, Engin; Mamedov, Amirullah M.
    The structural, mechanical, electronic and optical properties of orthorhombic PtSi and PtGe were investigated using norm-conserving pseudopotentials within the local density approximation in the frame of density functional theory. The calculated lattice parameters and bulk modulus for PtSi and PtGe have been compared with the experimental and theoretical values. The second-order elastic constants were calculated, and the other related quantities such as the Young's modulus, shear modulus, Poisson's ratio, anisotropy factor, sound velocities and Debye temperature have also been estimated. The linear photon-energy dependent dielectric functions and some optical properties such as the energy-loss function, the effective number of valance electrons and the effective optical dielectric constant were calculated. Our structural estimation and some other results are in agreement with the available experimental and theoretical data.