Ab initio Study on the Structural Stability and Magnetism of Metastable A_3B Phases in Ni—Au (Cu, Zn, Al) Binary Systems

摘要

Based on the projector augmented-wave method, ab initio calculations are performed for 20 representative binary Ni–Au, Ni–Cu, Ni–Zn, and Ni–Al alloys at A3B composition. The calculations reveal that the DO_(22) Ni_3Au, Ni_3Cu, Ni_3Zn, and Ll_2 Ni_3Al are more energetically stable than their respective competitive structures, indicating that the four structures may be formed in some appropriate conditions. The calculations indicate that different structures have small effects on the magnetic moments for Ni_3Au and Ni_3Cu alloys, while have large effects on the magnetic moments for Ni_3Zn and Ni_3Al alloys. It is also predicted that there is strong hybridization between Ni 3d and Cu 3d states in Ni_3Cu and Ni 3d and Au 5d states in Ni_3Au alloys and little hybridization in Ni_3A1 and Ni_3Zn, which may significantly affect on structural stability and magnetism of these structures. The calculations suggest that the magnetism may increase the energetic stability of these structures. It is hoped that these interesting finding would stimulate further experimental investigations on the binary metastable Ni–Au (Cu, Zn, Al) intermetallics.