DYNAMICS OF SURFACE PROFILE EVOLUTION THROUGH SURFACE-DIFFUSION

We have studied the evolution, mediated by surface diffusion, of perio dic corrugations on a surface using Monte Carlo simulations on a solid -on-solid (SOS) model. Above the roughening temperature T-R, for both unidirectional and bidirectional sinusoidal corrugations of wavelength L, the amplitude h decays exponentially with time h/h(0) approximate to exp(-alpha t), with t/L(4) scaling in agreement with Herring-Mullin s theory. Below the roughening temperature, there is a gradual transit ion to a power-law decay of the amplitude as the temperature is lowere d. The wavelength scaling varies with the substrate temperature and th e periodicity of the corrugation in the two orthogonal transverse dire ctions. Well below T-R, the amplitude in unidirectional sinusoidal cor rugations evolves with time according to h/h(0) approximate to(1 + lam bda t)(-1), with t/L(5) scaling for diffusion-limited kinetics, in agr eement with the theory of Ozdemir and Zangwill [Phys. Rev. B 42, 5013 (1990)]. In bidirectional sinusoidal corrugations, profile decay is dr iven by a combination of line-tension and step-step entropic repulsion , in agreement with the theory of Rettori and Villain [J. Phys. (Paris ) 49, 257 (1988)].