Growth of thin platinum films on Cu(1 0 0): CAICISS, XPS and LEED studies M. Walker, C.R. Parkinson, M. Draxler, C.F. McConville * Department of Physics, University of Warwick, Coventry CV4 7AL, UK Received 9 November 2004; accepted for publication 24 March 2005 Available online 13 April 2005 Abstract The growth mode of platinum films on the Cu(1 0 0) surface up to a coverage of 2.75 ML has been studied using co-axial impact collision ion scattering spectroscopy (CAICISS), X-ray photoelectron spectroscopy and low energy electron diffraction. CAICISS data show the formation of a Cu–Pt alloy at room temperature in the top three atomic layers at sub-monolayer Pt coverage. As the coverage increases up to 2.75 ML the formation of a Pt overlayer is observed in conjunction with the near surface region becoming Pt-rich, indicating the onset of layer-by-layer growth. Subsequent annealing shows a significant migration of Pt into the bulk Cu at a temperature of 300 °C. Evidence for a more ordered surface after annealing is also presented. Ó 2005 Elsevier B.V. All rights reserved. Keywords: Low energy ion scattering (LEIS); Low energy electron diffraction (LEED); X-ray photoelectron spectroscopy; Platinum; Copper; Alloys 1. Introduction Alloys and bimetallic surfaces have received much attention in recent years due to their impor- tance in many modern technological processes (e.g. heterogeneous catalysis and magnetic record- ing [1–3]). The deposition of one metal on a sub- strate of a second metallic species (e.g. Pt on Cu(1 0 0)) allows production of alloys with control- lable concentrations, and may present surfaces with different characteristics to those of single crystal alloy surfaces (e.g. Cu x Pt y (1 0 0)). The Cu–Pt surface alloy system has been the subject of numerous studies, ranging from Cu deposition on Pt surfaces [4–7], to single crystal alloy surfaces [8,9] and Pt deposition on Cu surfaces [10–25]. The formation of Cu–Pt alloys on the Cu(1 1 1) surface by Pt deposition and subsequent annealing has been widely studied using many 0039-6028/$ - see front matter Ó 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.susc.2005.03.050 * Corresponding author. Tel.: +44 24 7652 4236; fax: +44 24 7669 2016. E-mail address: c.f.mcconville@warwick.ac.uk (C.F. McConville). Surface Science 584 (2005) 153–160 www.elsevier.com/locate/susc