Size disproportionation among nanocluster transformations.

Controllable transformation is a prerequisite to the in-depth understanding of structure evolution mechanisms and structure-property correlations at the atomic level. Most transformation cases direct the directional evolution of nanocluster sizes, i.e. , size-maintained, size-increased, or size-reduced transformation, while size disproportionation was rarely reported. Here, we report the Au-doping-induced size disproportionation of nanocluster transformation. Slight Au-doping on the bimetallic (AgCu) 43 nanocluster produced its trimetallic derivative, (AuAgCu) 43 , following a size-maintained transformation. By comparison, the (AgCu) 43 nanocluster underwent a size-disproportionation transformation under heavy Au alloying, leading to the formation of size-reduced (AuAgCu) 33 and size-increased (AuAgCu) 56 nanoclusters simultaneously. Such a size disproportionation among the nanocluster transformations was verified by the thin-layer chromatography analysis. This work presented a novel nanocluster transformation case with a size disproportionation characteristic, expected to provide guidance for the understanding of cluster size evolutions.