Crystal structure of the mirror symmetry 10H-type long-period stacking order phase in Mg–Y–Zn alloy

Abstract The crystal structure of the 10H-type long-period stacking order structure in Mg–Y–Zn alloy was investigated by first-principle calculations. The calculated results show that the accurate positions and distinctive arrangement of Zn and Y atoms in the most stable 10H-type LPSO phase exhibit mirror symmetry with respect to the atomic layer C 6 , which agrees well with the experimental observations. Theoretical calculations still indicate that the mirror symmetry 10H-type ABACBCBCAB phase is not distorted, the lattice distortion of other LPSO phases may originate from the asymmetry of Zn element in the chemical order and stacking order. The obtained electronic density of states (DOS) reveals the underlying mechanism for mirror symmetry of 10H-LPSO phase.