Table Of ContentCollective Diffusion on Surfaces:
Correlation Effects and Adatom Interactions
ASeriespresentingtheresultsofscientificmeetingssupportedundertheNATOScience
Programme.
TheSeriesispublishedbylOSPress,Amsterdam,andKluwerAcademicPublishersinconjunction
withtheNATOScientificAffairsDivision
Sub-Series
I. LifeandBehaviouralSciences lOSPress
II. Mathematics,PhysicsandChemistry KluwerAcademicPublishers
III.ComputerandSystemsScience lOSPress
IV.EarthandEnvironmentalSciences KluwerAcademicPublishers
TheNATOScienceSeriescontinuestheseriesofbookspublishedformerlyastheNATOASISeries.
The NATOScience Programmeofferssupportforcollaborationincivilsciencebetweenscientistsof
countriesoftheEuro-AtlanticPartnershipCouncil.Thetypesofscientificmeetinggenerallysupported
are"AdvancedStudyInstitutes"and"AdvancedResearchWorkshops",andtheNATOScienceSeries
collects together the results of these meetings.The meetings are co-organized bijscientists from
NATOcountriesandscientistsfrom NATO'sPartnercountries- countriesoftheCISandCentraland
EasternEurope.
AdvancedStudyInstitutesarehigh-leveltutorialcoursesofferingin-depthstudyoflatestadvances
inafield.
Advanced ResearchWorkshopsare expert meetingsaimedatcriticalassessmentofafield, and
identificationofdirectionsforfutureaction.
AsaconsequenceoftherestructuringoftheNATOScienceProgrammein1999,theNATOScience
Serieswasre-organizedtothefoursub-seriesnotedabove.Pleaseconsultthefollowingwebsitesfor
informationonpreviousvolumespublishedintheSeries.
http://www.nato.inVscience
http://www.wkap.nl
http://www.iospress.nl
http://www.wtv-books.de/nato-pco.htm
riesII:Mathematics,PhysicsandChemistry- Vol.29
Collective Diffusion on Surfaces:
Correlation Effects and Adatom
Interactions
edited by
M.C. Tringides
Department of Physics and Astronomy,
Iowa State University,
Ames, Iowa, U.SA
and
z.
Chvoj
Institute of Physics,
Academy of Sciences of the Czech Republic,
Prague, Czech Republic
Springer Science+Business Media, B.V.
Proceedings of the NATO Advanced Research Workshop on
Collective Diffusion on Surfaces: Correlation Effects and Adatom Interactions
prague, Czech Republic
2-6 October 2000
A C.I.P. Catalogue record for this book is available from the Library of Congress.
ISBN 978-0-7923-7116-8 ISBN 978-94-010-0816-7 (eBook)
DOI 10.1007/978-94-010-0816-7
Printed on acid-free paper
AII Rights Reserved
© 2001 Springer Science+Business Media Dordrecht
Originally published by Kluwer Academic Publishers in 2001
Softcover reprint of the hardcover 1 st edition 2001
No part of the material protected by this copyright notice may be reproduced or utilized in
any form or by any means, electronic or mechanical, including photocopying, recording
or by any information storage and retrieval system, without written permission from the
copyright owner.
TABLE OF CONTENTS
Preface. ix
I. Surface Diffusion atEquilibrium
QuasielasticHeliumScatteringStudiesofSurfaceDiffusion:
TheDiffusionBarrier . ..
A. P.GrahamandJ. P.Toennies
ExperimentalAspectsofMetalParticleDiffusiononaSiliconSurface 11
JiriSlezak, PavelSchukrinov,Alexei Savchenkov, PingoMutombo,
andVladimirChab
SurfaceDynamicsofSteppedSi(001)Studied byTemporalLEED
Spectroscopy . 23
K. Kammler, M. HornVon Hogen, N.Voss, M.Tringides, A. Menzel,
andE. H. Conrad
ElectricCurrentInducedAsymmetryofSurfaceDiffusion-Instabilityof
VicinalCrystalSurfaces . 33
S. S. Stoyanov, J. J.Metois,andV. Tonchev
MemoryEffectsandMemoryFunctionsinSurfaceDiffusion 47
T. Hjelt, E. Kuusela, J. M. Lahtinen,T. Ala-Nissila, I.Vattulainen,and
S. C. Ying
Driven DiffusioninaModeloftheOIW(110)System . 59
M.A. Zaluska-Kotur, StanislawKrukowski, and LukaszA. Turski
SurfaceDiffusionandReal-SpaceRenormalizationGroup .. 71
A. A. Tarasenko, L. Jastrabik, F. Nieto,andC. Uebing
SurfaceDiffusion NearPhaseTransitions . 83
F. Nieto,A. Tarasenko,andC. Uebing
II. Surface Diffusionfrom ProfileEvolution Methods
SurfaceHeterodiffusioninAdsorbedandCoadsorbedOverlayersofLi, Sr,
andCuontheWandMo(112)Surfaces ...... 97
A. T. Loburets, N. B. Senenko,Yu. S. Vedula, andA. G. Naumovets
MetalHeterodiffusionon MetallicSurfaces: CaseofPbonCu 107
C. Cohen, G. Prevot, and D. Schmaus
StepEffectsonSurfaceDiffusion: AComprehensiveStudyofCOon Pt(111) 117
XudongXiao
Adsorption, Desorption,andDiffusionofPotassiumon MetalandOxide
Surfaces 129
G. Kerner, I.M. Danziger,W. Zhao,andM.Asscher
III. Surface DiffusionUnderNon-equilibriumConditions
DynamicsofInteractingAdparticlesUnderNon-EquilibriumConditions .. 143
Z.Chvoj
vi
Statistical-MechanicalDescriptionofNonequilibriumProcessesinInteracting
LatticeGases . 157
V. S.Vikhrenko,G. S. Bokun,andVa.G.Groda
ModelStudiesofCollectiveDiffusion .. 169
I.Vattulainen
StudyofNon-EquilibriumSurfaceDiffusion FromanInitialStep-Concentration
ProfileWithaNewProbability-BasedContinuumMethod 179
M. R. DudekandM. C.Tringides
IV. Diffusion MechanismsinGrowthProcesses
DiffusiononandINSurfaces: TheAtomicSlidePuzzle . 191
J.W. M. Frenken, R.VanGastel, S. B.VanAlbada, E. Somfai,
andW. VanSaarloos
DecayofTwo-DimensionalIslandsonAg(110) . 201
K. Morgenstern, E. Leegsgaard,andF. Besenbacher
SurfaceMorphologyanddynamics: UsingAb-initioTotalEnergiestomakethe
MostoftheSTMData . 213
PeterJ. Feibelman
Substrate-MediatedInteractiononAg(111)SurfacesFromFirstPrinciples .. 225
KristenA. FichthornandMatthiasScheffler
DiffusionofAdatomsandSmallClustersonMissing-Row-Reconstructed
Surfaces..................................................... 237
F. MontalentiandR. Ferrando
EffectsofAdsorbatesonSubmonolayerGrowth 247
MiroslavKotrla, JoachimKrug, andPavel$milauer
SUrfactantsinSemiconductorHeteroepitaxy: Thermodynamicsand/orkinetics? ........ 259
IvanMarkov
V. SubstrateEffectsand Surface Diffusion
NonlinearDiffusionandSliding Friction . 273
S. C. Ying, E.Granato,andT.Ala-Nissila
SelectiveActivationDynamics: AMinimalPathApproach............................................ 285
L. Y.Chen, P. L. Nash,andS. C. Ying
LongJumpsinSurfaceDiffusionInvestigatedbyStochasticEquations .. 295
R. Ferrando, R. Spadacini,andG. E.Tommei
AnalyticalKineticTheoryofSingle-ParticleandCollectiveSurface
Diffusion . 305
S. Yu. Krylov
AdatomIslandDiffusiononMetalFCC(100)Surfaces 317
O. S.Trushin, J. Hirvonen, J. Heinonen,P. Salo, M.Alatalo, T.Ala-Nissila,
I. Koponen, andJ.Merikoski
Paths, Barriers,andPrefactorsforAdatomDescentfromAgClustersonAg(111) 327
T. S. Rahman, A. Kara,A. Karim, A. AI-Rawi
vii
CorrelatedDiffusionofAdatomsand IslandsontheLowIndexedSurfacesofNoble
MetalsandAlloys . .. 339
A. E. Evangelakis
AuthorIndex . 351
SubjectIndex .. 353
Preface
As materials research focuses into finding ways to control the growth of atomic
scale structures, there is correspondingly increasing emphasis on to the problem
of surface diffusion. Clearly surface diffusion is the key process, which
determines how atoms move on the surface. Controlling this motion can lead to
the easy fabrication of well-controlled nanostructures broadening the present
possibilities in nanotechnology.
The paradigm ofsurface diffusion has outgrown its standard textbook description
as a random walk on a rigid substrate. In real systems for more complex
situations are encountered: interacting atoms are commonly present on the
surfacewith their motions highly correlated, different phases form on the surface
with different dynamics, large concentration gradients drive the system far away
from the linear response regime, rich metastable structures form as a result of
balanced interplay between different kinetic processes, substrate relaxation can
change the energy landscape and thediffusion barriers, etc.
The motivation behind this ARW was to bring together the international
community working on these problems. We felt that the large number of
researchers, new results, and well-formulated open questions in this area require
some form of integration in a single forum. The ARW and the upcoming
proceedings book with papers by the majority of the participants has provided
thisforum.
The meeting was not planned as a continuation of the earlier NATO ASI in
Rhodes in 1996, although several people have participated in both meetings.
The goal ofthe Rhodes meeting was to bring together workers on the atomistic
aspects of surface diffusion with workers on many-body, collective effects to
initiate a dialogue between the two groups. The Prague meeting has
concentrated more on the latter.
The meeting was held in the beautiful city of Prague, which offers an unparallel
combination of physical beauty, historical treasures, cultural life, and
cosmopolitan spirit. After the rigor of the scientific lectures, it was relaxing to
stroll along the banks ofthe river Vltava orto climb up the unending steps to the
top ofthe castle to be rewarded with the panoramic view ofthe city. Maybe the
only uncooperative element was the weather, to ensure that the experience was
real.
It is impossible in the short preface to give justice to the excitement of the
presentations and discussions ofthe meeting. The excitement can be found by
reading the chapters that follow. We are limited in simply making a general
observation that we believe is shared by most practitioners in the field: how the
gap between theory and experiment is narrowing. This narrowing between
theory and experimentcan be seen from several advances. Realisticsimulations
ix
x
of complicated physical phenomena can include many competitive microscopic
processes over longer time scales; analytic methods have been developed to
describe surfacediffusion infar-fram-equilibrium experiments; the behaviorofthe
diffusion coefficientcloseto aphasetransition hasbeen predicted and measured
in similar systems; new experimental methods can probe the system close to
equilibriumtotestfundamental predictionsofstatistical mechanics.
The success ofthe meeting is a result ofthe hard work ofseveral people. We
would liketofirstthankthe members ofthe Organizing Committee (ProfessorsV.
Chab and R. Ferrando) who have been full of ideas about the scientific and
social program. The meeting would not have run so smoothly without the
dedicated commitment of the student support (M. Ma_in, H. Chvojova,
P.Jelinek). The professionalism and expertise ofthe veteran of several NATO
meetings, Rebecca Shivvers, is greatly appreciated for the high quality of the
proceedings volume. The great hospitality displayed by the Czech people
involved with the meeting (both scientists and non-scientists) has flooded the
meeting with unbounded warmth and care.
Ofcourse, nomeeting ispossiblewithoutgenerousfinancial support. We greatly
thank the NATO Scientific Division for providing us the majority ofthe funds for
the meeting, in their tradition of supporting so many high quality scientific
meetings year-afier-year. We thank the support of the Czech Academy of
Science and the Helsinki Institute ofTechnology, which have offered additional
financial support to cover the cost of the facilities and support student
participation.
We believe the meeting has catalyzed the formation of a cohesive cluster of
scientists working on the collective aspects of surface diffusion. The strong
interactions between the participants displayed at the meeting proves that the
cluster is highly stable beyond critical size. Future meetings to follow-up on the
goals and vision ofthe Prague meeting should beanticipated.
Ames and Prague, March 2001.
QUASIELASTIC HELIUM SCATTERING STUDIES OF SURFACE
DIFFUSION: THE DIFFUSION BARRIER
A. P. GRAHAMl AND J. P. TOENNIES2
Max-Planck Insitut fiir Stromungsforschung,
Bunsenstrafte 10,
D-37073 Gottingen,
Germany
Abstract. Some results of recent quasielastic helium scattering (QHAS)
on the surface diffusionofadatoms and adsorbates are reviewed. Particular
emphasis is placed on the evaluation ofthe effective diffusion barrier ener
gies measured and their dependenceon the system and temperature range.
1. Introduction
During the last 12 years, improvements in the helium atom scattering
(HAS) method, particularly in resolution, intensity, and stability, have per
mitted the quasielastic broadening of the elastic peak due to adsorbate
diffusion to be determined with high accuracy and reliability [1]. The de
pendence ofthe quasielastic widthon momentum transfer (or wave vector)
and temperature have, typically, beenanalyzed usinganalogies toquasielas
tic neutronscattering (QNS) [2], enablingthe diffusionofa large numberof
adsorbatejadatom-substrate systems to be measured [1, 3]. With only two
exceptions, namely PbjPb(llO) [4] and NijNi(llO) [1], the effective dif
fusion barriers obtained with quasielastic helium atom scattering (QHAS)
have been significantly lower than anticipated, prompting speculation that
the QHAS results have been incorrectly interpreted [5]. Consequently, it is
appropriate to discuss the diffusion parameters obtained with QHAS, par
ticularly the barrierto diffusion, and how they relate to the resultsofother
Ipresent address: Infineon Technologies AG, Corporate Research, Otto-Hahn-Ring6,
D-81739 Munich, Germany.
2Corresponding author: [email protected]
M.e. TringidesandZ. Chvoj(eds.),
CollectiveDiffusiononSurfaces:CorrelationEffectsandAdatomInteractions, 1-10.
©2001 KluwerAcademicPublishers.
