Morphology and electronic structure of the Ca/Si(111) system
| Autor: | J. A. Carlisle, K. M. Jones, J.W. Dickinson, M. S. Turner, A. A. Baski, Steven C. Erwin |
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| Rok vydání: | 2001 |
| Předmět: |
Reflection high-energy electron diffraction
Chemistry Fermi level Surfaces and Interfaces Electronic structure Condensed Matter Physics Surfaces Coatings and Films law.invention symbols.namesake X-ray photoelectron spectroscopy Electron diffraction law Phase (matter) Materials Chemistry symbols Atomic physics Scanning tunneling microscope Surface reconstruction |
| Zdroj: | Surface Science. 476:22-34 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/s0039-6028(00)01112-2 |
| Popis: | The Ca/Si(1 1 1) system has been studied using reflection high-energy electron diffraction, scanning tunneling microscopy (STM), synchrotron radiation photoemission, and first-principles total-energy calculations. This system forms a series of odd-order n×1 (n=3,5,7,…) reconstructions that culminate with a 2×1 phase at 0.5 ML. Our results indicate that the honeycomb-chain-channel (HCC) model accounts well for the observed data from the 3×1 surface. We propose a model for the 2×1 phase based upon π-bonded Seiwatz Si chains, and explain the intermediate odd-order phases as appropriate combinations of the 2×1 Seiwatz chains and 3×1 HCC chains. Calculated surface energies based on this model correctly predict that for increasing Ca coverage, the 3×1, 5×1, and 2×1 phases will each appear as stable phases. Simulated STM images are in excellent agreement with experiment. The Ca 3×1 phase exhibits a suppression of emission at the Fermi level and a local 2a (a=0.38 nm ) corrugation along the rows in STM images, both of which are consistent with the formation of either a charge-density wave or a one-dimensional correlated insulator. |
| Databáze: | OpenAIRE |
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