Electronic structure and optical properties of TaC from the first principles calculation

Abstract.: The electronic and optical properties of tantalum carbide TaC have been calculated using the full-potential linearized augmented-plane-wave method within the local density approximation scheme for the exchange-correlation potential. We find that the optical spectra can be extremely sensitive to the Brillouin zone sampling. The influence of relativistic effects on the dielectric function is investigated. It is shown that the scalar-relativistic correction is much more important than spin-orbit coupling. Our results are found to be in good agreement with the available experimental data. The determinant role of a band structure computation with respect to the analysis of optical properties is discusse

Electronic structure and optical properties of TaC from the first principles calculation

The electronic and optical properties of tantalum carbide TaC have been calculated using the full-potential linearized augmented-plane-wave method within the local density approximation scheme for the exchange-correlation potential. We find that the optical spectra can be extremely sensitive to the Brillouin zone sampling. The influence of relativistic effects on the dielectric function is investigated. It is shown that the scalar-relativistic correction is much more important than spin-orbit coupling. Our results are found to be in good agreement with the available experimental data. The determinant role of a band structure computation with respect to the analysis of optical properties is discussed

Full potential calculation of structural, electronic and optical properties of KMgF₃

A theoretical study of the structural, electronic and optical properties of KMgF₃ is presented using the full-potential linearized augmented plane wave method (FP-LAPW). In this approach, the local density approximation was used for the exchange-correlation potentials. First, we present the main features of the structural and electronic properties of this compound, where the electronic band structure shows that the fundamental energy gap is indirect. The contribution of the different bands was analysed from the total and partial density of states curves. The different interband transitions have been determined from the imaginary part of the dielectric function. The results are compared with previous calculations and with experimental measurements. The present work also deals with the behaviour of electronic properties, namely, the energy band gaps, and the valence bandwidth of KMgF₃ subject of hydrostatic pressures up to 30 GPa

Full potential linearized augmented plane wave calculations of structural and electronic properties of GeC, SnC and GeSn

cited By 28International audienceA theoretical study of structural and electronic properties of GeC, SnC and GeSn is presented using the full potential linearized augmented plane wave method. In this approach, the generalized gradient approximation was used for the exchange-correlation potential. Results are given for lattice constant, bulk modulus and its pressure derivative in both zinc-blende and rocksalt structures. Band structure, density of states and band gap pressure coefficients in zinc-blende structure are also given. The results are compared with previous calculations and with experimental measurements. © 2003 Elsevier B.V. All rights reserved

First-principles calculations of optical properties of GeC, SnC and GeSn under hydrostatic pressure

cited By 25International audienceWe present first-principles of the full-potential linearized augmented plane wave calculations of the effect of hydrostatic pressure on the optical properties of zinc-blende GeC, SnC and GeSn compounds. The refractive index and its variation with hydrostatic pressure are well described. An accurate calculation of linear optical functions (refraction index and its pressure derivative, and both imaginary and real parts of the dielectric function) is performed in the photon energy range up to 15 eV. The predicted optical constants agree well with the available experimental and theoretical ones. © 2004 Elsevier B.V. All rights reserved

First-principle study of structural, electronic and elastic properties of SrS, SrSe and SrTe under pressure

cited By 63International audienceThe full-potential linearized augmented plane wave method (FP-LAPW) within the generalized gradient approximation (GGA) is used to calculate the electronic band structures and the total energies of SrS, SrSe and SrTe in NaCl- and CsCl-type structures. The latter provide us with the ground state properties such as lattice parameter, bulk modulus and its pressure derivative, elastic constants and the structural phase stability of these compounds. The transition pressures at which these compounds undergo structural phase transition from NaCl to CsCl phase are calculated. The energy band gaps at room conditions in NaCl structure and volume dependence of the band gaps in the CsCl structure are presented. The pressure and volume at which band overlap metallization occurs are also determined. The ground state properties, the transition and metallization pressures (volumes) are found to agree with the experimental and other theoretical results. The elastic constants at room conditions in both NaCl and CsCl structures are calculated and compared with the available theoretical results for SrSe while, for SrS and SrTe, the elastic constants are not available. © 2003 Elsevier B.V. All rights reserved

Structural, electronic, elastic and high-pressure properties of some alkaline-earth chalcogenides: An ab initio study

cited By 34International audienceThe full-potential linearized augmented plane wave method (FP-LAPW) within the generalized gradient approximation (GGA) is used to calculate the electronic band structures and the total energies of BaS, CaSe and CaTe in NaCl and CsCl-type structures. The latter provide us with the ground states properties such as lattice parameter, bulk modulus and its pressure derivative, elastic constants and the structural phase stability of these compounds. The transition pressures at which these compounds undergo the structural phase transition from NaCl to CsCl phase are calculated. The energy band gaps and their volume dependence in NaCl and CsCl type-structures are investigated. The pressure and the volume at which band overlap metallization occurs are also determined. The ground state properties, the transition and metallization pressures (volumes) are found to agree with the experimental and other theoretical results. The elastic constants at equilibrium in both NaCl and CsCl structures are calculated and compared with the available theoretical results for CaSe, while for BaS and CaTe the elastic constants are not available. © 2005 Elsevier B.V. All rights reserved