Ab initio study on the structural and elastic properties of MAlSi (M = Ca, Sr, and Ba)

Using first-principles total energy calculations within the local density approximation (LDA) and the generalized gradient approximation (GGA). we have investigated the structural and elastic properties of MAN (M = Ca, Sr, and Ba) crystallized in hexagonal C32 structure. The lattice parameters and independent elastic constants of MAlSi have been obtained from LDA and GGA calculations. The bulk modulus along crystallographic axes of single crystal, shear modulus, Young's modulus, and Poisson's radio of MAISi are also estimated. The calculated elastic moduli of MAN compare well with available experimental values. In addition, the mechanical anisotropy of MAN is also discussed. (C) 2007 Elsevier Ltd. All rights reserved.