Surface diffusion, rapid alloying, microcluster

Rapid alloying (RA) is a fast diffusion process that was experimentally discovered by Yasuda, Mori, and co-workers (YM) in binary microclusters. By using an evaporator, they deposited individual solute atoms (Cu) on the surface of host nano-sized clusters that are supported by amorphous carbon him at room temperature. YM observed the alloying behavior with a transmission electron microscope in in situ condition as schematically described in Fig. 1. In Ref. 7 it is demonstrated that Au clusters promptly changed into highly concentrated, homogeneously mixed (Au-Cu) alloy clusters. RA is similarly observed in various nano-sized binary clusters, such as (Au-Ni), (In-Sb), (Au-Zn), and (Au-Al) [7]. They examined the presence and absence of RA for clusters of different sizes. Consequently, YM summarize the unusual features of RA as follows ... 

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