Abstract
By means of low energy electron diffraction intensity versus voltage (LEED IV) analysis with the help of scanning tunneling microscope (STM), the crystallography of GaAs(001)-c(4×4) surface has been determined. STM images indicate that the atomic structure of the surface at room temperature does not have rigorously a p2mm symmetry, which has been assumed in all the analyses conducted so far. Asymmetric three-dimer model, which consists of three As dimers in the unit cell on an As-terminated unreconstructed surface, has led to the best fit between the experimental and calculative IV curves with the Pendry's reliability factor of 0.27. The center dimer among the three is tightly dimerized with the bond length of 2.13 Å, while the outer two have achieved less complete dimerization with the bond length of 3.02 Å. Contrary to the case for the Si(001), it is not buckling perpendicular to the surface but in-plane twisting that dominantly makes the dimers asymmetric, which involves remarkably short bond length for some of the backbonds.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
