Electron diffraction of CS₂ nanoclusters embedded in superfluid helium droplets

We report experimental results from electron diffraction of CS₂ nanoclusters embedded in superfluid helium droplets. From detailed measurements of the sizes of doped droplets, we can model the doping statistics under different experimental conditions, thereby obtaining the range of cluster sizes of CS₂. Using a least squares fitting procedure, we can then determine the structures and contributions of dimers, trimers, and tetramers embedded in small droplets. While dimers prefer a stable gas phase structure, trimers and tetramers seem to forgo the highly symmetric gas phase structures and prefer compact cuts from the crystalline structure of CS₂. In larger droplets containing more than 12 CS₂ monomers, the diffraction profile is consistent with a three-dimensional nanostructure of bulk CS₂. This work demonstrates the feasibility of electron diffraction for in situ monitoring of nanocluster formation in superfluid helium droplets.