First-principles and empirical molecular dynamics calculations were made of the effect of size and surface reconstruction upon the atomic structure properties of small Ge nanoparticles (1 to 2.5nm). Systems with ideal H-passivated surfaces, or bare reconstructed surfaces were considered. It was shown that the surface reconstruction led to a very strong volume contraction of the nanoparticles; equivalent to an applied pressure of 4GPa for a 2nm nanoparticle. It was found that the surface reconstruction significantly shifted the optical mode peak of the vibrational spectrum; thereby preventing straightforward size-determination using Raman spectroscopy.

Surface Reconstruction Effects on Atomic Properties of Semiconducting Nanoparticles. L.Pizzagalli, G.Galli: Materials Science and Engineering B, 2002, 96[2], 86-9