In, Sn dimers on Si(100)2x1 surface: ab initio calculations and STM experiments

Low dimensional systems and especially 1D systems can present very original properties. It is now well established that the deposition of Group III (A l, Ga, In) or IV (Si, Ge, Sn, Pb) atoms on the Si(100)2 x 1 surface results in the formation of lines of dimers. We have determined the geometry of Sn , In and In-Sn mixed dimers on Si(100)2 x 1 surface both from theoretical a nd experimental points of view. Ab initio calculations are performed with t he generalized gradient correction to the local density approximation of th e density functional theory. Theoretical results and ultrahigh vacuum (UHV) scanning tunneling microscopy (STM) images are compared and discussed in t he light of simple arguments based on changes in the hybridization states o f the orbitals of the surface ad dimer atoms. (C) 2000 Elsevier Science B.V . All rights reserved.