We examined the surface segregation behavior of Si in amorphous AuSi alloys using ab initio molecular dynamics simulations within density functional theory. For a thin Au70Si30 film, our simulations predict Si surface enrichment that leads to a stoichiometry close to Au 60Si40 in the surface layer. The surface structure exhibits a rather ordered Au3Si2 phase, which somewhat differs from the bulk Au60Si40 structure that exhibits a tendency of random hard-sphere packing. We also discuss the origin of the Si surface segregation based on analysis of segregation-induced changes in the atomic and electronic structure of the AuSi alloy surface.
|Number of pages||5|
|Journal||Journal of Physical Chemistry C|
|State||Published - 25 Feb 2010|