Core-Shell Formation and Juxtaposition in Fe and Si Hybrid Clusters Prepared by Controlling the Collision Stages

Fe and Si hybrid clusters are co-deposited on substrates in a double-glow-discharge-source-type plasma-gas-condensation system, and observed by transmission electron microscopy, scanning transmission electron microscopy, X-ray diffraction and Mossbauer spectroscopy. Core-shell Fe/Si clusters, in which chemically heterogeneous bcc Fe-Si cores are covered by amorphous-like Si shells, are obtained on the substrate when Fe and Si cluster nuclei collide with each other at an early stage (without setting the partition plate between the two sources). On the other hand, Fe and Si clusters are juxtaposed on the substrate when their nuclei collide with each other at a late stage (with setting of the partition plate). These results demonstrate that we can obtain various hybridized states of Fe and Si clusters by controlling the collision stages.