First-principles calculations of elastic constants of DO 3-Mg3 RE (RE = Sc, Y, La, Ce, Lu)

Abstract

The elastic constants of DO3-Mg3 RE (RE = Sc, Y, La, Ce and Lu) have been calculated at T = 0 K by applying the projector augmented wave (PAW) method within the generalized gradient approximation (GGA). The polycrystalline shear modulus, Young's modulus, Poisson's ratio and the anisotropic ratio of DO3-Mg3 RE are also estimated. The density of states and bonding charge densities of DO3-Mg3 Ce and DO3-Mg3 Er are calculated to understand the bonding characteristics of Mg3 RE. The calculated results indicate that the rare earth (RE) additions can improve the elastic modulus of Mg alloys. The predicted elastic constants of DO3-Mg3 RE provide helpful guidance for the design of novel Mg alloys. © 2008 The Royal Swedish Academy of Sciences.