Abstract
The atomic-scale structure of Zn2+ incorporated at the CaCO3 (1014) surface by adsorption from solution was determined by X-ray standing wave triangulation and surface extended X-ray absorption fine structure spectroscopy. At low coverage (approximately 0.1 ML), Zn2+ substitutes for Ca2+ in the surface layer. Structural relaxation of the adjacent in-plane CO2-3 ions in the host surface is shown by the reduced nearest-neighbor distance of Zn-O relative to Ca-O. Relaxation of the Zn2+ ion in the out-of-plane direction is shown by the displacement of its lattice position from the ideal Ca2+ position. These relaxations, resulting in a local lattice buckling feature at the Zn2+ adsorption site, can be fully explained as the combined effect of the electrostatic relaxation of the nearest-neighbor anions in response to the smaller size of Zn2+, and the bonding asymmetry due to surface truncation.
Original language | English (US) |
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Pages (from-to) | L976-L982 |
Journal | Surface Science |
Volume | 415 |
Issue number | 1-2 |
DOIs | |
State | Published - Sep 30 1998 |
Keywords
- Adsorption
- Calcite
- Surface extended X-ray absorption fine structure (SEXAFS)
- Surface structure
- X-ray standing waves (XSW)
- Zinc
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry