Anisotropic Roughening of Vicinally Miscut Ag(110) - X-Ray-Reflection Profile Analysis Using the Domain-Matrix Method

The roughening behavior of a vicinally miscut Ag(110) surface has been studied with x-ray diffraction using synchrotron radiation. The lateral profiles recorded at different q(perpendicular to) were analyzed with (a) the domain-matrix method, an evaluation scheme for diffraction profiles, and (b) using a conventional power-law profile shape analysis. Both methods result in a roughening temperature of T-R=900+/-20 K (=0.73T(m)). The type of the roughening transition is consistent with the predictions of the anisotropic body-centered solid-on-solid (=six-vertex) model with step creation energies of J(x)=45+/-3 meV and J(y)=60+/-3 meV along [(1) over bar 10] and [001], respectively. At low temperatures, a two-component (bimodal) step distribution corresponding to a bunching of steps is identified.