Dynamics of Step Fluctuations on a Chemically Heterogeneous Surface of Al/Si(111)-(√3x√3)
The analysis of the dynamics of equilibrium step fluctuations has been extended to a chemically heterogeneous surface. The multicomponent reconstructed Al/Si~111!-~)3)! surface has been studied using variabletemperature scanning tunneling microscopy at elevated temperatures. The temporal correlation functions for both single steps and step arrays follow a t1/2 dependence over the entire temperature range ~770–1020 K!, consistent with a rate limiting mechanism of random attachment and detachment of atoms at step edges. The alternative mechanism, diffusion from step-to-step, is shown to be inconsistent with more detailed analytic approximations to the correlation function for the measured step-step separation. An activation energy of 1.9 eV and the major kinetic parameters that govern surface mass transport and step equilibration processes have been determined.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 860123
- Report Number(s):
- PNNL-SA-42659; TRN: US200523%%90
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, 66(8):085327-1 - 085327-5, Vol. 66, Issue 8
- Country of Publication:
- United States
- Language:
- English
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