In this paper, the phononic and thermal properties of tungsten disulfide have been studied. The aim of this study was to investigate the phonon and thermal properties such as heat capacity and enthalpy. The calculations are performed within the framework of density functional theory by pseudo-potential methood and by Quantum Espresso computational package and their exchange-correlation function...

  Using the forced oscillator method (FOM) and the transfer-matrix technique, we numerically investigate the nature of the phonon states and the wave propagation, in the presence of an external force, in the chains composed of Fibonacci lattices of type site, bond and mixing models, as the quasiperiodic systems. Calculating the Lyapunov exponent and the participation ratio, we also study the lo...

In this paper, according to the  density functional theory and semiharmonic approximation and solving kohen's equations using plane wave, band structure, phonon scattering; Dielectric tensor, Bourne effective charge, Raman cross-section; We calculated the infrared and specific heat capacity of indium phosphide in two-phase structures on zincblend (ZB) and salt rock (Rs). The results show that t...

TiO2 nanocrystallites in rutile phase with 68 nm dimensions have been synthesized by sol–gel technique. The structure and particle sizes have been determined by X-ray diffracttion and SEM characterizations. Different factors in the rutile phase broadenings and shifts of the Raman modes at different temperatures, especially at high temperatures, have been studied.The effect of particle size, non...

In this paper, the phonon, dynamic and thermal properties of indium nitride in two phases are investigated. The calculations are performed using the pseudopotantial method in the framework of density functional theory and by using the quantum-espresso Package. In the calculations, the exchange-correlation terms of LDA, GGA and PBE0 approximation are used. Investigation of phononic  properties s...

Electron-phonon coupling parameters are calculated for La2-x BaxCuO4 cuprate superconductor in a wide range of dopings, from undoped to overdoped compounds. In this study we aim to study the quality of such calculations based on DFT method so, the results of σ GGA+U electronic structure calculations are also investigated. The obtained value for electron-phonon coupling is in the same order of p...