Ultrathin V films on Pt(111): a structural study by means of X-ray photoelectron spectroscopy and diffraction

A detailed structural study of V growth on Pt (111) has been performed mainly by means of angle resolved X-ray photoelectron spectroscopy and diffraction, with the aid of multiple scattering cluster-spherical wave simulations of the diffraction curves. Vanadium on Pt (Ill)grows with a two-domain bulk-like bcc(lll)stacking largely incoherent with the substrate, at least up to a thickness of eight equivalent monolayers. For thicker layers, an orientational transition is observed, leading to a six-domain bulk-like bcc (110) structure. Although bcc (Ill)-oriented V is preserved in the thicker layer, we cannot exclude the fact that some of the initially (Ill) ultrathin film has been partially restructured to the (110) orientation when the critical thickness associated with the transition has been exceeded. Strong three-dimensional clustering of the overlayer is observed for any investigated thickness which supports a Volmer-Weber growth of the V film. Our findings are compared to literature data concerning the growth of Cr on the same substrate. (C) 1999 Elsevier Science B.V. All rights reserved.