Elastic properties of single- and polycrystalline LaFeAsO, SrFe2As2, and LiFeAs basic phases for new FeAs superconductors

Abstract

The elastic coefficients (Cij), bulk compression moduli (B), and shear moduli (G) of layered tetragonal LaFeAsO, SrFe2As2, and LiFeAs crystals, which are potential basic phases for new superconductors of the 1111-, 122-, and 111-FeAs groups, respectively, have been calculated from first principles using the full-potential linearized augmented plane wave (FLAPW) method with an exchange-correlation potential in the generalized gradient approximation (GGA). Numerical estimates of the bulk moduli, shear moduli, Young’s moduli, and Poisson’s ratios of the corresponding polycrystalline ceramics have been obtained for the first time.