Facet-Guiding Deposition of Size-Selected Au Cluster Size on MgO Cube

The size-selected Au (923 ± 23 atoms) cluster soft-landed on amorphous carbon and MgO(100) surface were imaged by transmission electron microscope (TEM) and aberration-corrected scanning transmission electron microscopy (AC-STEM). Au923 clusters presents multiplicity geometries on amorphous carbon and epitaxial relationship with MgO(100) surface. It is found that there is a projected size of Au923 clusters shrinking when landed on the MgO surface. This is due to the limited observation direction caused by the epitaxial relationship between the facet of Au923 clusters and Mg(100) lattice. This study highlights the different observation direction of electron microscopy images of clusters can result in the change of projected area. Such visual size changes can not be neglected in the cluster studies at atomic resolution.