کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425427 | 1395855 | 2007 | 6 صفحه PDF | دانلود رایگان |

We have performed density-functional theory calculations to study the atomic structure of the K/Pd(1Â 0Â 0)-p(2Â ÃÂ 2) and -c(2Â ÃÂ 2) surfaces formed at 0.25Â ML and 0.5Â ML, respectively. We find that K atoms prefer the hollow site with the K adsorption height 2.44Â Ã for p(2Â ÃÂ 2) and 2.50Â Ã c(2Â ÃÂ 2). The first interlayer spacing (d12) of the Pd(1Â 0Â 0) substrate appears slightly contracted from the bulk value as Îd12Â =Â â0.8% and â0.3% for p(2Â ÃÂ 2) and c(2Â ÃÂ 2), respectively. The calculated contraction Îd12Â =Â â0.3% for c(2Â ÃÂ 2) is not in accord with the expansion Îd12Â =Â +1.3% reported by a low-energy electron diffraction (LEED) study. As the origin of this difference, a possibility of hydrogen contamination of the surface sample used in the LEED study is suggested: Our calculations show that the d12 of K/Pd(1Â 0Â 0)-c(2Â ÃÂ 2) increases linearly with the coverage of H coadsorption, which leads to an estimation for the H coverage of the surface sample as 0.1-0.4Â ML.
Journal: Surface Science - Volume 601, Issue 3, 1 February 2007, Pages 852-857