2018-09-26T13:15:58Z
http://digital.csic.es/dspace-oai/request
oai:digital.csic.es:10261/8485
2016-02-16T04:01:46Z
com_10261_115
com_10261_3
col_10261_368
00925njm 22002777a 4500
dc
Riikonen, Sampsa
author
Sánchez-Portal, Daniel
author
2008-04-17
We present here a comprehensive search for the structure of the Si(553)-Au reconstruction. More than 200 different trial structures have been studied using first-principles density-functional calculations with the SIESTA code. An iterative procedure, with a step-by-step increase in the accuracy and computational cost of the calculations, was used to allow for the study of this large number of configurations. We have considered reconstructions restricted to the topmost bilayer and studied two types: (i) "flat" surface-bilayer models, where atoms at the topmost bilayer present different coordinations and registries with the underlying bulk, and (ii) nine different models based on the substitution of a silicon atom by a gold atom in different positions of a π-bonded chain reconstruction of the Si(553) surface. We have developed a compact notation that allows us to label and identify all these structures. This is very useful for the automatic generation of trial geometries and for counting the number of inequivalent structures, i.e., structures that have different bonding topologies. The most stable models are those that exhibit a honeycomb-chain structure at the step edge. One of our models (model "f2") reproduces the main features of the room temperature photoemission and scanning-tunneling microscopy data. Thus, we conclude that this model is a good candidate for the high temperature structure of the Si(553)-Au surface.
Phys. Rev. B 77, 165418 (2008)
1098-0121
http://hdl.handle.net/10261/8485
10.1103/PhysRevB.77.165418
Bonds (chemical)
Density functional theory
Gold
Iterative methods
Photoemission
Scanning tunnelling microscopy
Silicon
Surface reconstruction
Surface structure
Systematic investigation of the structure of the Si(553)-Au surface from first principles