Vicinal surfaces: free energy, terrace width distribution and step correlation functions

The equilibrium morphology of vicinal surfaces is governed by thermal kink creation energies and step-step interactions. Such parameters can be determ ined within microscopic step models by means of the statistical analysis of surface images such as those provided by STM. A versatile multi-step trans fer matrix (strip) method is introduced to calculate thermodynamical averag es. The correlation function of step displacements along step edges, the te rrace width distribution and the free energy are thus obtained. The applica bility of various one-step and many-step formulae is discussed, and propert ies of the capillary wave approximation are given. Within this approximatio n, the width of the terrace width distribution at the roughening temperatur e is found to be universal. (C) 1999 Elsevier Science B.V. All rights reser ved.