EFFECT OF CLUSTER-SIZE ON PHASE-STABILITY IN NM-SIZED AU-SB ALLOY CLUSTERS

The effect of cluster size on the phase stability in nanometre (nn)-si zed Au-Sb alloy clusters has been studied by means of transmission ele ctron microscopy (TEM), in order to see the difference in the phase st ability between a bulk material and the corresponding nm-sized cluster . When the cluster size is reduced below approximately 6 nm in mean di ameter, it is difficult to from distinct interfaces between two differ ent phases (i.e. solid solution and AuSb2) in the interior of individu al Au-Sb alloy clusters. Analytical electron microscopy using an elect ron probe of approximately 1 nm in diameter revealed that the solid so lubility of antimony in a few nm-sized gold clusters increases by at l east one order of magnitude compared to that for the corresponding bul k material.