Study Of The Ground-state Geometric Structures Of Bimetallic Clusters Fe-Ni With A Genetic Algorithm

Clusters, as the transition state between microcosmic atom, molecule and macroscopical solid-state matter, have many peculiar characters. As transition metal clusters, the clusters of iron, cobalt and nickel have attracted considerable attention by many academicians because of their novel properties in magnetism and catalytic activity. The bimetallic clusters can improve the stability and own new fancy properties as comparing that of pure clusters. In those years many scientists pay attention to the structure and character of FeNi bimetallic clusters. But to our knowledge, no results have been reported for the particular investigation of the ground state geometrical structures of FenNim(n+m=13,38)clusters. In this paper, we use Gupta many-body potential combined with genetic algorithm to perform a systematic study of the ground state structural properties of the bimetallic clusters FenNim (n+m=13, 38). Our results show that:1. The ground-state geometrical structures of the 13-atom bimetallic clusters all possess the icosahedron, and the Fe atoms tend to occupy the central part of the icosahedron priorly with incressing the number of Fe atoms;2. The truncated octahedra are identified as the ground-state geometries of the 38-atom bimetallic clusters FenNim in the range of n≤15 and 34≤n≤38, otherwise an icosahedral fragment prefers;3. Fe1Ni12, Fe7Ni31 and Fe14Ni24 are recognized as the magic-number clusters, and we proposal a simple model based on the effective number of bonds to explain the reason.