Using atomic force microscopy and spot-profile analyzing low energy electron diffraction, the existence of a striking faceting instability in Al(110) homo-epitaxy was observed; characterized by the formation of nanocrystals with well-defined facets. These hut-shaped nanocrystals were over tenfold higher than the total film coverage, and coexist

in a bimodal growth mode with much shallower and more populous surface mounds. Density functional theory calculations were further used to elucidate the microscopic origin of the faceting instability, induced by surprisingly low activation barriers for adatom ascent at step edges and island corners.

Nanocrystal Formation and Faceting Instability in Al(110) Homoepitaxy - True Upward Adatom Diffusion at Step Edges and Island Corners. F.B.de Mongeot, W.Zhu, A.Molle, R.Buzio, C.Boragno, U.Valbusa, E.G.Wang, Z.Zhang: Physical Review Letters, 2003, 91[1], 016102 (4pp)