Journal de Physique I

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DOI: 10.1051/jp1:1997141
J. Phys. I France 7 (1997) 1455-1473

Relaxatin of a Grooved Profile Cut in a Crystalline Surface of High Symmetry

Erwan Adam, Anna Chame, Frédéric Lançon and Jacques Villain

Département de Recherche Fondamentale sur la Matière Condensée, CEA Grenoble, 38054 Grenoble Cedex 9, France

(Received 17 February 1997, revised 19 June 1997, accepted 27 June 1997)

Abstract
The smoothing of artificial grooves on a high-symmetry crystal surface below its roughening transition is investigated in the light of a one-dimensional model. In the case of diffusion dynamics, a new, kinetic, attractive interaction between steps opposes the contact repulsion and tends to flatten the top and the bottom of the profile in the transient state anterior to complete smoothing. This phenomenon, which is absent from continuum models, is weaker, but still present in real, two-dimensional surfaces.

Kinetic Monte Carlo simulations have been performed for large modulation amplitudes in contrast with previous works. The relaxation time $\tau$ scales with the wavelength $\lambda$ as $\tau \propto \lambda^3$ for diffusion dynamics and as $\lambda$ as $\tau \propto \lambda^2$ for evaporation dynamics. In the case of evaporation dynamics, the transient profile is sinusoidal. In the case of surface diffusion the profile presents blunted parts at the top and at the bottom, which result from the kinetic attraction between steps.