AVS 50th International Symposium
    Surface Science Wednesday Sessions
       Session SS-WeP

Paper SS-WeP8
Using Island Step-Edge Fluctuations to Determine Absolute Step Energies: Application to Pb(111)@footnote 1@

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: T.J. Stasevich, University of Maryland, College Park
Authors: T.J. Stasevich, University of Maryland, College Park
F. Szalma, University of Maryland, College Park
T.L. Einstein, University of Maryland, College Park
Correspondent: Click to Email
It is well known that the equilibrium shape of an adatom or vacancy island can be used to extract the step free energy (or line tension) of the island step-edge up to a scale factor. Obtaining the absolute step energy, however, requires a deeper analysis. Recently it has been shown that by analyzing the island step-edge fluctuations about the equilibrium island shape, the desired absolute step energy can be obtained.@footnote 2,3@ We exploit this theoretical framework to analyze the temporal fluctuations of two-dimensional Pb(111) adatom and vacancy islands measured with scanning-tunneling microscopy.@footnote 4@ We report on our ongoing analysis and discuss the degree to which subtle transformations are needed to obtain eigenmodes from the conventinal multipole modes. With the aid of movies, we also discuss techniques used to find the equilibrium island shape, as well as tools used to analyze the fluctuations and, thus, determine the absolute step free energies. @FootnoteText@ @footnote 1@Work at UM supported by NSF Grants MRSEC DMR 00-80008 and EEC-0085604. @footnote 2@S. Kodambaka et al., Phys. Rev. B 67 (2003) 035409; S.V. Khare et al., Surf. Sci. 522 (2003) 75. @footnote 3@ F. Szalma and T.L. Einstein, submitted to SS1@footnote 4@ K Thürmer et al., Phys. Rev. Lett. 87 (2001) 186102.