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 main ly by means of angle resolved X-ray photoelectron spectroscopy and diffract ion, with the aid of multiple scattering cluster-spherical wave simulations of the diffraction curves. Vanadium on Pt (Ill)grows with a two-domain bul k-like bcc(lll)stacking largely incoherent with the substrate, at least up to a thickness of eight equivalent monolayers. For thicker layers, an orien tational transition is observed, leading to a six-domain bulk-like bcc (110 ) structure. Although bcc (Ill)-oriented V is preserved in the thicker laye r, we cannot exclude the fact that some of the initially (Ill) ultrathin fi lm has been partially restructured to the (110) orientation when the critic al thickness associated with the transition has been exceeded. Strong three -dimensional clustering of the overlayer is observed for any investigated t hickness which supports a Volmer-Weber growth of the V film. Our findings a re compared to literature data concerning the growth of Cr on the same subs trate. (C) 1999 Elsevier Science B.V. All rights reserved.