Microstructure and electronic characteristics of the 6H-type ABACAB LPSO structure in Mg_(97)Zn_1Y_2 alloy

摘要

Microstructure and electronic characteristics of the 6H-type ABACAB LPSO structure in Mg_(97)Zn_1Y_2 alloy are investigated by means of first-principles calculation within the generalized gradient approximation. The accurate positions of the solid solution atoms Y and Zn together with the arrangement rules are determined theoretically and the lattice distortion of the 6H-type ABACAB structure is also discussed in comparison with the 6H-type ABCBCB' structure. The stability is also analyzed on the basis of the calculated cohesive energy, which reveals that Y element stabilizes the structure significantly. The electronic characteristics show that the Y element enhances the strength of alloy due to the presence of Mg-Y covalent bonding and the hybridization between Mg and Zn is relatively strong in entire region which contributes to improve the alloy's ductility.