Glass Nature of the Cluster

To fully understand the chemical and physical properties of DENs, it is important to know the lattice structure of these ultrasmall particles ( 2 nm). A general question is whether these small particles have a periodic 3D structure and well-defined crystal facets as their bulk counterparts do. For big nanoparticles, high-resolution transmission electron microscopy (HRTEM) and XRD spectroscopy are two commonly used and powerful techniques to characterize lattice structure. However, the lattice structure of ultrasmall nanoparticles is largely unknown because HRTEM and XRD are either not applicable or can t provide meaningful information. 

8 Experimental XRD (a) and the corresponding PDFs G(r) for 1.6-nm An particles, (b) Best model PDFs (line in red) and an experimental PDF for 26-nm Pd particles (line in blue) are also shown. Reprinted with permission from ref. [91]. Copyright 2008 American Chemical Society 

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