Combined Ab Initio Total Energy Density Functional Calculations and Scanning Tunneling Microscopy Experiments of the #beta#Sic(001) c(4x2) Surface

摘要

First-principle total energy density functional calculations using a cluster approach demonstrate that the recently STM-imaged c(4x2) reconstruction of the fully Si-terminated #beta#-SiC(001) surface originates from symmetric Si dimers having not only alternating heights but also alternating bond lengths. The Si-terminated #beta#-SiC(001) surface is thus strucutrally totally different from the Si(001) c(4x2) reconstruction. These theoretical predictions bring new insights into the recent alternately up- and down- dimer model (AUDD model) proposed on the ground of STM measurements on #beta#-SiC c(4x2) surface.