Electronic Origin of Phase Stability in Mg-Zn-Y Alloys with a Long-Period Stacking Order

Abstract

The origin of the phase stability of 18$R$ Mg-Zn-Y alloys with a long-period stacking order (LPSO) is studied using first-principles calculations. We calculate the heat of formation as a function of the number of Zn vacancies to discuss the role of Zn atoms. The calculated convex hull indicates that the Zn atoms in the LPSO alloys are stable even if they number about half of the Y atoms. The bonding state with Zn $p$ orbitals leads to the stability of the LPSO structure because the partial density of states of Mg nearest to the solute cluster forms a valley structure.

References in corpus (4)

• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Thermodynamic Stability of Mg-based Ternary Long-Period Stacking Ordered Structures
• Improved tetrahedron method for the Brillouin-zone integration applicable to response functions
• Origin of phase stability in Fe with long-period stacking order as an intermediate phase in cyclic $\gamma$-$\epsilon$ martensitic transformation