title: Computational study of structural, elastic and electronic properties of lithium disilicate (Li(2)Si(2)O(5)) glass-ceramic.
abstract: The objective of this study is to investigate theoretically the structural, elastic and electronic properties of Lithium Disilicate (LD) crystal (Li2Si2O5), using the pseudo potential method based on Density Functional Theory (DFT) with the Local Density Approximation (LDA) and the Generalized Gradient Approximation (GGA). The calculated structural properties namely the equilibrium lattice parameters and cell volume are in good agreement with the available experimental results. However, for the LD crystal elastic moduli: Shear modulus G, Young's modulus E and Poisson's ratio ν we have found a discrepancy between our theoretical values and experimental ones reported in polycrystalline sample containing LD crystals. The calculated elastic properties show that LD is more rigid compared with other components. We also investigated the mechanical stability of Li2Si2O5 compound and we have noticed that this compound is stable against elastic deformations. On the basis of shear to bulk modulus ratio analysis, we inferred that Li2Si2O5 compound is brittle in nature. In order to complete the fundamental characteristics of this compound we have measured the elastic anisotropy. Our results for the energy band structure and Density of States (DOS) show that Li2Si2O5 compound has an insulator characteristic.
authors.affiliation: Unité de recherche sciences des matériaux et applications, Département de Physique, Faculté des Sciences Exactes, Université Constantine 1, Constantine 25000, Algérie. Electronic address: biskriz@yahoo.fr.
authors.forename: Zine Elabidine
authors.initials: ZE
authors.lastname: Biskri
authors.affiliation: Laboratoire des matériaux magnétiques, Département de physique, Faculté des sciences, Université Djillali LIABES, Sidi-Bel-Abbès 22000, Algérie. Electronic address: habib_rached@yahoo.fr.
authors.forename: Habib
authors.initials: H
authors.lastname: Rached
authors.affiliation: Unité de recherche sciences des matériaux et applications, Département de Physique, Faculté des Sciences Exactes, Université Constantine 1, Constantine 25000, Algérie.
authors.forename: Merzoug
authors.initials: M
authors.lastname: Bouchear
authors.affiliation: Laboratoire des matériaux magnétiques, Département de physique, Faculté des sciences, Université Djillali LIABES, Sidi-Bel-Abbès 22000, Algérie.
authors.forename: Djamel
authors.initials: D
authors.lastname: Rached
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry*; D055119:Elastic Modulus; D004583:Electrons; D005898:Glass / Q000737:chemistry*; D011789:Quantum Theory
chemical_list: C493120:lithia disilicate; D003776:Dental Porcelain
keywords: Elastic properties; Electronic properties; Glass-ceramics; Lithium disilicate crystal; Structural properties