Structure and Stability of Nanoscale Bimetallic Clusters

Abstract

This paper reviews the recent research and development of bimetallic clusters. Small bimetallic nanoscale clusters often have physical and chemical properties that are distinct from those of their pure bulk counterparts and suggestive of novel applications. Their chemical and physical properties can be controlled by varying the cluster size and composition as well as the temperature. Therefore the starting point for an understanding of bimetallic clusters is the study of their structures. The typical most stable structure: cuboctahedron, decahedron, icosahedron and Marks decahedron etc. According to the elemental distribution in bimetallic clusters, they can be divided into solid solution type, core/shell, eutectic-like etc. Complete phase separation is found in some bimetallic systems in specific conditions. The most stable structure of a bimetallic cluster is affected by the interatomic interaction potential, especially the alloying interaction, radius of the metal atom or the nearest neighbor distance in its stable bulk crystalline, temperature, concentration of each component, and the size of the clusters. In certain dynamic synthesis conditions such as substrate, non-most stable structure can form and exist, and can transform into a stable structure under some conditions such as heating.