S 53 Shein, I. R. Elastic properties and chemical bonding in ternary arsenide SrFe2As2 and quaternaryoxyarsenide LaFeAsO – Basic phases for new 38–55 K superconductors fromfirst principles / I. R. Shein, A. L. Ivanovskii // Physica C. - 2009. - Vol. 469. - P. 15-19 : il. - Bibliogr. : p. 18-19 (31 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): РАСЧЕТЫ ПЕРВОПРИНЦИПНЫЕ -- СВЕРХПРОВОДНИКИ -- СВОЙСТВА УПРУГИЕ -- FeAs Аннотация: Here we report the first-principle FLAPW-GGA calculations of the elastic properties of two related layered phases, namely, the ternary arsenide SrFe2As2 and the quaternary oxyarsenide LaFeAsO – basic phases for the newly discovered "122" and "1111" 38–55 K superconductors. The independent elastic constants (Cij), bulk moduli, compressibility, and shear moduli are evaluated and discussed. The numerical estimates??of the elastic parameters of the polycrystalline SrFe2As2 and L\aFeAsO ceramics are performed??for the first time. Additionally, the peculiarities of chemical bonding in these phases are discussed |