Effect of kink-rounding barriers on step edge fluctuations
| Autor: | Joachim Krug, Jouni Kallunki |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Condensed Matter - Materials Science
Materials science Statistical Mechanics (cond-mat.stat-mech) Condensed matter physics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Surfaces and Interfaces Activation energy Function (mathematics) Edge (geometry) Condensed Matter Physics Surfaces Coatings and Films Einstein relation Materials Chemistry Kinetic Monte Carlo Diffusion (business) Scaling Condensed Matter - Statistical Mechanics Energy (signal processing) |
| Zdroj: | Surface Science. 523:L53-L58 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/s0039-6028(02)02435-4 |
| Popis: | The effect that an additional energy barrier E_{kr} for step adatoms moving around kinks has on equilibrium step edge fluctuations is explored using scaling arguments and kinetic Monte Carlo simulations. When mass transport is through step edge diffusion, the time correlation function of the step fluctuations behaves as C(t) = A(T) t^{1/4}. At low temperatures the prefactor A(T) shows Arrhenius behavior with an activation energy (E_{det} + 3 epsilon)/4 if E_{kr} < epsilon and (E_{det} + E_{kr} + 2 epsilon)/4 if E_{kr} > epsilon, where epsilon is the kink energy and E_{det} is the barrier for detachment of a step adatom from a kink. We point out that the assumption of an Einstein relation for step edge diffusion has lead to an incorrect interpretation of step fluctuation experiments, and explain why such a relation does not hold. The theory is applied to experimental results on Pt(111) and Cu(100). 11 pages, 4 eps figures |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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