Continuous, atomically flat, and epitaxial Bi(111) films could be grown on Si(001). The inherent strain of 2.3% between the Bi(111) and Si(001) lattices was relieved by the formation of a grating like one-dimensional misfit dislocation array at the hetero-interface. The lattice distortions around each dislocation gave rise to a pronounced height depression Δh=0.12nm of the surface, which results in a spot splitting in low-energy electron diffraction and a height contrast in scanning tunnelling microscopy. Using such surface profiles across these depressions, the Burgers vector of the underlying isolated non-interacting dislocations was estimated to be 0.377nm. For thicker Bi films the ordering of the dislocation network was increased. This reflects an increase of repulsive interaction between neighbouring dislocations.

Nanoscale Dislocation Patterning in Bi(111)/Si(001) Heteroepitaxy. G.Jnawali, H.Hattab, C.A.Bobisch, A.Bernhart, E.Zubkov, R.Möller, M.Horn-von Hoegen: Surface Science, 2009, 603[13], 2057-61