Spontaneous alloying of zinc atoms into gold clusters and formation of compound clusters

The alloying behavior of zinc atoms into gold clusters has been studied using a 200 kV transmission electron microscope equipped with a double-source evaporator in the specimen chamber. Isolated gold clusters were first prepared on a supporting film of amorphous carbon, and zinc atoms were then deposited onto the same film. Upon the deposition of zinc, the gold clusters quickly changed into Au-Zn solid solution clusters, disoroderd ${\mathrm{\alpha }}_1$-${\mathrm{Au}}_3$Zn clusters, or ordered β’-AuZn clusters depending on the amount of deposited zinc. The spontaneous alloying which results in the formation of compound clusters is observed here for the first time.