A first principles study of Rh on Mo(111) and W(111) surfaces

Using local density functional calculations, we studied the morphological changes of Mo(111) and W(111) upon the adsorption of an ultrathin film of Rh, The unusual relaxations induced by Rh on Mo(111) and W(111) surfaces should be caused by competing several factors such as Smoluchowski smoothing effect: change of atomic interactions, and charge transfer between overlayer and substrate, It was found that both Rh/Mo(111) and Rh/W(111) can facet to {211} when the Rh coverage reaches one physical monolayer. The {211} facets should coexist with the (111) planar surfaces, which is substantially due to thermodynamic effects, and the onset annealing temperature for inducing facets of Rh/Mo(111) and Rh/W(111) should be higher than that for some other metal overlayers such as Pd. (C) 2001 Elsevier Science B.V. All rights reserved.