کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425694 | 1395863 | 2006 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Surface composition and structure of palladium ultra-thin films deposited on Ni(1 1 1) Surface composition and structure of palladium ultra-thin films deposited on Ni(1 1 1)](/preview/png/5425694.png)
Ultra-thin palladium films deposited on the Ni(1 1 1) surface were characterized by X-ray photoelectron spectroscopy (XPS), low-energy electron diffraction (LEED) and X-ray photoelectron diffraction (XPD). For low coverage, LEED shows a (1 Ã 1) pattern similar to that of the substrate. For intermediate coverage, the LEED pattern displays extra spots around the main (1 Ã 1) spots, resembling a Moiré coincidence pattern, probably associated with the formation of Pd bi-dimensional islands oriented in different directions on the Ni(1 1 1) surface. The results obtained by XPS and XPD corroborate this finding. The LEED pattern displays this structure up to 500 °C. Annealing at 650 °C brings back the (1 Ã 1) pattern, which is associated with a Pd island coalescence and alloy formation by Pd diffusion in the first atomic layers of the Ni(1 1 1). In this paper we present a detailed study of this surface structure via a comparison between XPD experiment and theory.
Journal: Surface Science - Volume 600, Issue 11, 1 June 2006, Pages 2268-2274