A Monte Carlo investigation into the equilibrium properties of the Si{111}surface

Monte Carlo simulations of the Si(111) surface at equilibrium have been per formed. No evidence is found for the existence of a disordered flat phase, as previously reported in literature. Examination of the specific heat as a function of temperature, the height-height correlation function and an ord er parameter for the Si(111) surface reveals only one phase transition, the familiar Kosterlitz-Thouless roughening transition. It is shown that the a rgument for the existence of a disordered flat phase is based on a spurious effect on the specific heat that can be attributed to the presence of isol ated adatoms. The presence of such adatoms, with no bonds to the bulk of th e crystal at all, is excluded in our Monte Carlo simulations. (C) 1999 Else vier Science B.V. All rights reserved.