二元A1-Ni纳米团簇结合能的尺寸和成分依赖性研究

Size and composition dependent cohesive energy of Al-Ni bimetallic nanoclusters

利用分子动力学的方法研究了二元A1-Ni团簇结合能的尺寸和成分依赖性。研究表明，低于300K时，团簇的结构不依赖于成分，仍然保持面心立方结构。成分一定时，团簇的结合能随着尺寸的增大而增大；尺寸一定时，A1-Ni团簇的结合能先随着Ni含量的增大而增大，当Ni含量为O．75时，达到极值，而后随着Ni含量的增大而减小，说明Al0.25Ni0.75为最稳定的结构。对于A1-Ni团簇进一步研究表明，Al有表面聚集的趋势。

The size and composition dependent cohesive energy of A1-Ni bimetallic nanoclusters is studied by molecular dynamics simulation method. It is found that the structures are independent of the composition and remain face-centered cubic. In specified composition, the cohesive energy increases with increasing of size. In specified size, the cohesive energy firstly increases with increasing of atomic percentage of Ni （xNi）, and reaches the maximum if XNi=0.75, and then decreases with increasing of xNi, which means that is the most stable structures. Furthermore, it is shown that Al atoms have the tendency of surface segregation.