Access

Article


Nature Materials 7, 308 - 313 (2008)
Published online: 9 March 2008 | doi:10.1038/nmat2132

Subject Categories: Nanoscale materials | Characterisation and analytical techniques

Coordination-dependent surface atomic contraction in nanocrystals revealed by coherent diffraction

W. J. Huang1,2, R. Sun1,2, J. Tao1,2, L. D. Menard2,3, R. G. Nuzzo2,3 & J. M. Zuo1,2


Surface atoms have fewer interatomic bonds than those in the bulk that they often relax and reconstruct on extended two-dimensional surfaces. Far less is known about the surface structures of nanocrystals. Here, we show that coherent diffraction patterns recorded from individual nanocrystals are very sensitive to the atomic structure of nanocrystal surfaces. Nanocrystals of Au of 3–5 nm in diameter were studied by examining diffraction intensity oscillations around the Bragg peaks. Both results obtained from modelling the experimental data and molecular dynamics simulations strongly suggest inhomogeneous relaxations, involving large out-of-plane bond length contractions for the edge atoms (approx0.2 Å); a significant contraction (approx0.13 Å) for {100} surface atoms; and a much smaller contraction (approx0.05 Å) for atoms in the middle of the {111} facets. These results denote a coordination/facet dependence that markedly differentiates the structural dynamics of nanocrystals from bulk crystalline surfaces.


MORE ARTICLES LIKE THIS

These links to content published by NPG are automatically generated.

NEWS AND VIEWS

Coherent diffraction Giant molecules or tiny crystals?

Nature Materials News and Views (01 Apr 2008)

Microscopy X-ray nanovision

Nature News and Views (06 Jul 2006)

See all 6 matches for News And Views