Size-dependent K-edge EXAFS study of the structure of free Ar clusters

Physical review letters 78(9), 1675 - 1678 (1997). doi:10.1103/PhysRevLett.78.1675
Extended x-ray absorption fine structure (EXAFS) spectroscopy is used to study the size-dependent structural evolution of free clusters. K-edge EXAFS data are obtained for Ar clusters in beams having mean cluster size ranging from 12 to 2900 atoms per cluster. EXAFS analysis yields size-dependent features which indicate the presence of an fcc structure at ⟨N⟩≥200. It has been proposed in the literature that small rare-gas clusters have an icosahedral structure. The transition of this structure to the experimentally observed fcc lattice of rare-gas solids has been of long-standing interest and debate. The implications of our results are discussed in this light.
Published by APS, College Park, Md.