Impurity-induced faceting of Pb surfaces

Impurity-induced faceting of Pb(110) and (111) surfaces is studied by ultra -high vacuum scanning electron microscopy, high spatial resolution Auger el ectron spectroscopy and low energy electron diffraction. It is found that f aceting is induced by Rh segregation which probably forms a low symmetry su rface compound with complicated alignment with respect to bulk crystal and high index facets. The segregation is reversible with some hysteresis and o ccurs with maximum rate at 110 degrees C. Possible causes of this phenomeno n and several consequences are discussed. (C) 1998 Elsevier Science B.V. Al l rights reserved.