Point defects and Zn-doping in defective Laves phase C15 MgCu2: A first-principles study Academic Article uri icon

abstract

  • 2016 Published by Elsevier B.V. Employing first-principles calculations, the point defect in C15 Laves phase MgCu2 is studied. The formation enthalpies of point defects and defective C15 MgCu2 compound show that the dominating defect structure is MgCu and CuMg antisite defect on Mg-rich and Cu-rich side of off-stoichiometry, respectively. The concentration of various point defects as a function of composition of MgCu2 is analyzed from grand canonical statistics. The calculated local geometrical variation around defect demonstrates an apparent size effect, and the electronic densities of states and charge density difference distributions indicate the gradually weaker bonding from MgCu to VCu and from CuMg to VMg systems. Furthermore, doping of Zn atom in defective MgCu2 has been investigated. It is found that Zn has a stronger preference for occupying the Cu sublattice than for Mg sublattice because of the relative lower formation enthalpy. The electronic structure further reveals that the stability of Zn-doped system is associated with the stronger covalent bonds between Cu-Cu and Zn-Cu atoms.

published proceedings

  • Computational Materials Science

author list (cited authors)

  • Zheng, J., Tian, X., Shao, L., Pan, X., Tang, P., & Tang, B.

citation count

  • 8

complete list of authors

  • Zheng, Jie||Tian, Xiao||Shao, Lin||Pan, Xiong-Ze||Tang, Ping-Ying||Tang, Bi-Yu

publication date

  • September 2016