Extended x-ray-absorption fine structure has been used in conjunction with the aggregation technique to investigate the structure of copper microclusters (7 to 15 Å mean diameter). The crystallographic structure of the microclusters is consistent with an fcc lattice. A small contraction of the nearest-neighbor distance was measured as a function of cluster size.

• Received 18 November 1985

DOI:https://doi.org/10.1103/PhysRevLett.56.2076