Angle-resolved photoemission extended fine-structure study of the structure ofp(2×2)K/Ni(111)
| Autor: | Z. Hussain, A. E. Schach von Wittenau, D.A. Shirley, Zhengqing Huang, L. Q. Wang |
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| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | Physical Review B. 47:13626-13635 |
| ISSN: | 1095-3795 0163-1829 |
| Popis: | Angle-resolved photoemission extended fine structure (ARPEFS) from the potassium 1s core level was measured for the quantitative structural determination of the p(2\ifmmode\times\else\texttimes\fi{}2)K/Ni(111) overlayer at 130 K. Our analysis of the ARPEFS \ensuremath{\chi}(k) curves detected along [111] and [771] showed that the potassium atoms are preferentially adsorbed on the atop sites, in agreement with a previous low-energy-electron-diffraction (LEED) study of the same system. The K-Ni bond length is 3.02\ifmmode\pm\else\textpm\fi{}0.01 \AA{}, yielding an effective hard-sphere radius of 1.77 \AA{} for potassium. The first-to-second-layer spacing of nickel is 1.90\ifmmode\pm\else\textpm\fi{}0.04 \AA{}, a 6.5% contraction from the bulk spacing of 2.03 \AA{}. Furthermore, the first nickel layer shows neither lateral reconstruction (0.00\ifmmode\pm\else\textpm\fi{}0.09 \AA{}) nor vertical corrugation (0.00\ifmmode\pm\else\textpm\fi{}0.03 \AA{}). A comparison of the structural parameters with those determined from the LEED study is presented. The limitations of Fourier analysis for site determination and the importance of comparing ARPEFS experimental data with theoretical simulations in both k space and r space are also discussed. |
| Databáze: | OpenAIRE |
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