Extended fine-auger-structure investigation of discontinuous chromium films

Abstract

We have used the extend fine-Auger-structure (EXFAS) technique to determine the short-range order of small chromium aggregates deposited in ultrahigh vacuum conditions on polycrystalline graphite. The interpretation of these extended features for structural studies follows very closely that of the extended X-ray absorption fine-structure spectroscopy. The high surface structural sensitivity of this technique is due to the low kinetic energy of the emitted electrons. The EXFAS features above the CrM 2,3VV Auger line have been analysed for different deposits of clean chromium clusters. We found a progressive contraction of the interatomic distance, with respect to the bulk, upon reducing the cluster size. This contraction amounts to about 10%.