STOCHASTIC MULLINS-HERRING EQUATION FOR A SOLID-ON-SOLID CRYSTAL

We derive a stochastic version of the Mullins-Herring equation-a continuum equation of motion for the relaxation of a solid surface to morphological equilibrium-for a two-dimensional solid-on-solid crystal. For Arrhenius-type desorption and surface diffusion kinetics, a linear Langevin equation describes the scaling behavior of the surface width. The final equation of motion is interpreted in terms of effective, macroscopic desorption and surface-diffusion parameters that reflect the full chemical activity of the surface.