Arsalan Akhtar | UCLouvain (University of Louvain) (original) (raw)

Videos by Arsalan Akhtar

Papers by Arsalan Akhtar

Resumen del poster presentado al 4th Scientific Meeting of BNC-b Students (JPhD), celebrado en Be... more Resumen del poster presentado al 4th Scientific Meeting of BNC-b Students (JPhD), celebrado en Bellatera (Espana) del 6 al 7 de junio de 2019.

Physica B: Condensed Matter, 2016

Abstract In this paper, we investigate the electronic and optical properties of MgO nanosheet in ... more Abstract In this paper, we investigate the electronic and optical properties of MgO nanosheet in (100) and (111) directions. Our calculations carried out under the framework of density functional theory (DFT) exploiting WIEN2K code with Full potential, periodic boundary conditions, augmented plane-wave basis sets and GGA approximation. Electronic results indicate that MgO(111) nanosheet has an indirect band gap of 3.67 eV and MgO(100) nanosheet has a direct band gap of 3.14 eV. MgO(100) nanosheet exhibit more ionic bonding than MgO(111) and MgO(111) has more covalent bonding than MgO(100) nanosheet. Moreover, the optical results indicate that variation of dielectric function in x direction is more than the z direction. DOS and imaginary part of the dielectric function survey confirm semiconductor properties with different bang gap for structures. Comparing the imaginary part of dielectric functions in x and z directions for two structures, blue and red shift have been observed respectively. Our results indicate that these two nanostructures are transparent in a wide range of energy spectra and have low reflectivity.

The Journal of Chemical Physics

International Journal of Modern Physics B

In the present study, we have investigated the phonon and thermodynamic properties of bulk zinc-b... more In the present study, we have investigated the phonon and thermodynamic properties of bulk zinc-blende CdS by first-principle calculations within the density functional theory (DFT) and the density functional perturbation theory (DFPT) method using the quasi harmonic approximation (QHA). We calculated the phonon dispersion at several high symmetry directions, density of phonon state, temperature dependence feature of Helmholtz free energy (F), internal energy, bulk modulus, constant-volume specific heat, entropy, coefficient of the volume thermal expansion and Grüneisen parameter estimated with the local density approximation (LDA) and generalized gradient approximation (GGA) for the exchange-correlation potential and compared them with each other. For internal energy, Helmholtz free energy, constant volume heat capacity and phonon entropy the LDA and GGA results are very similar. But, the LDA gives lattice constants that are smaller than GGA while phonon frequencies, bulk modulus a...

$Research paper thumbnail of Reflectivity and refractivity index enhancement in H doped ZnS graphene sheet: A first-principles study$

Optik - International Journal for Light and Electron Optics

Journal of Materials Science

Journal of Pharmaceutical and Biomedical Analysis

Journal of Electronic Materials

International Journal of Modern Physics B, 2016

The structural, electronic, optical and vibrational properties of Ni3C have been studied by densi... more The structural, electronic, optical and vibrational properties of Ni3C have been studied by density functional theory (DFT) framework with first-principles study. The obtained structural parameters are in good agreement with other works. The electronic study demonstrates metallic behavior of Ni3C since it has no energy gap at Fermi level. The optical parameters such as real and imaginary dielectric functions, loss function, conductivity, reflection, refraction indexes and absorption coefficients are studied. The phonon investigations confirm that the Ni3C bulk is dynamically stable and carbon has a major role in optical spectrum of the material at infrared region. Finally, the [Formula: see text] behavior of [Formula: see text] at low temperatures is obtained, as expected.