Electronic excitation processes in rare gas clusters studied by electron energy loss spectroscopy

• Published in: Applied surface science Vol. 256; no. 4; pp. 1046 - 1049
• Main Authors: Kubotera, Hayato, Sakai, Satoshi, Sekitsuka, Tatsuya, Tachibana, Takayuki, Hirayama, Takato
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 30.11.2009; Elsevier
• Subjects: Cluster; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron and ion emission by liquids and solids; impact phenomena; Electron energy loss spectra; Electron energy loss spectroscopy; Energy loss spectroscopy; Exact sciences and technology; Impact phenomena (including electron spectra and sputtering); Physics; Rare gas; Cluster; Energy loss spectroscopy; Rare gas; EEL spectroscopy; Mean free path; Electron spectra; Aggregate; Rare gases; Penetration depth
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2009.05.074

We present the electron energy loss spectra for Ar clusters as a function of incident electron energy and of cluster size. In spectra measured with 100 eV incident electron energy the bulk excitation peak becomes visible for a mean cluster size above 170 atoms per cluster. For 250 eV incident electron energy the bulk excitation peak is clearly observable even for a mean cluster size of 120 atoms per cluster. These experimental results are qualitatively reproduced by a simple calculation that accounts for the mean free path of electrons in Ar clusters; i.e., the penetration depth of incident electrons into the cluster.