Structural, elastic, electronic, optical and thermodynamic properties of KMgH3

• Published in: Solid state sciences Vol. 13; no. 3; pp. 647 - 652
• Main Authors: GHEBOULI, M. A, GHEBOULI, B, BOUHEMADOU, A, FATMI, M, BIN-OMRAN, S
• Format: Journal Article
• Language: English
• Published: Issy-les-Moulineaux Elsevier Masson 01.03.2011
• Subjects: Bulk modulus; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Debye temperature; Elastic constants; Elasticity, elastic constants; Electron states; Electronics; Exact sciences and technology; Lattice parameters; Mathematical analysis; Mathematical models; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Methods of electronic structure calculations; Optical properties; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of bulk materials and thin films; Physics; Structure of solids and liquids; crystallography; Structure of specific crystalline solids; Thermodynamic properties; Cubic lattices; Equilibrium constant; Density of states; Pressure effects; Elasticity; Polycrystals; Electron charge distribution; Hydrides; Sound velocity; Debye temperature; Optical properties; Elastic properties; Optical constants; Crystal structure; Shear properties; Elastic constants; Electronic properties; Experimental data; Shear modulus; Theoretical study; Mechanical properties; Perovskite-type hydride; Perovskites; Finite strain; Lattice parameters; APW calculations; Charge density; Pressure dependence; Young modulus; Electronic structure; Poisson ratio; Density functional method; Bulk properties; Aggregate; Thermodynamic properties; Ionic bonds
• ISSN: 1293-2558; 1873-3085
• DOI: 10.1016/j.solidstatesciences.2010.11.046

The structural, elastic, electronic, optical and thermodynamic properties of the cubic perovskite-type hydride KMgH3 have been investigated using pseudo-potential plane-wave method based on the density functional theory. Computed equilibrium lattice constant agrees well with the available experimental and theoretical data. The elastic constants and their pressure dependence are predicted using the static finite strain technique. A linear pressure dependence of the elastic stiffnesses is found. A set of isotropic elastic parameters and related properties, namely bulk and shear moduli, Young's modulus, Poisson's ratio, average sound velocity and Debye temperature are numerically estimated in the frame work of the Voigt-Reuss-Hill approximation for KMgH3 polycrystalline aggregate. The analysis of the site-projected l-decomposed density of states and charge density shows that the bonding is predominantly of ionic nature. Through the quasi-harmonic Debye model, in which the phononic effects are considered, the temperature effect on the lattice constant, bulk modulus, heat capacity and Debye temperature is calculated. Refractive index n( omega ) and extinction coefficient k( omega ), reflectivity spectra R( omega ) and electron energy loss L( omega ) for the KMgH3 compound. [Display Omitted]