Fluctuations, line tensions, and correlation times of nanoscale islands on surfaces

Abstract

We analyze in detail the fluctuations and correlations of the (spatial) Fourier modes of nano-scale single-layer islands on (111) fcc crystal surfaces. We analytically show that the Fourier modes of the fluctuations couple due to the anisotropy of the crystal, changing the power spectrum of the fluctuations, and that the actual eigenmodes of the fluctuations are the appropriate linear combinations of the Fourier modes. Using kinetic Monte Carlo simulations with bond-counting parameters that best match realistic energy barriers for hopping rates, we deduce absolute line tensions as a function of azimuthal orientation from the analyses of the fluctuation of each individual mode. The autocorrelation functions of these modes give the scaling of the correlation times with wavelength, providing us with the rate-limiting kinetics driving the fluctuations, here step-edge diffusion. The results for the energetic parameters are in reasonable agreement with available experimental data for Pb(111) surfaces, and we compare the correlation times of island-edge fluctuations to relaxation times of quenched Pb crystallites.

11 pages, 8 figures; to appear in PRB 70, xxx (15 Dec 2004), changes in MC and its implications

References in corpus (2)

• Orientation Dependence of Step Stiffness: Failure of SOS and Ising Models to Describe Experimental Data
• Dynamics of surface steps

Cited by in corpus (4)

• Low-Temperature Orientation Dependence of Step Stiffness on {111} Surfaces
• Correlations in nano-scale step fluctuations: comparison of simulation and experiments
• Interacting Steps With Finite-Range Interactions: Analytical Approximation and Numerical Results
• Anisotropic step stiffness from a kinetic model of epitaxial growth