Thermionic emission from small clusters: direct observation of the kinetic energy distribution of the electrons

✍ Scribed by H. Weidele; D. Kreisle; E. Recknagel; G. Schulze Icking-Konert; H. Handschuh; G. Ganteför; W. Eberhardt

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 489 KB
• Volume: 237
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(95)00344-4

✦ Synopsis

Photoelectron spectra of small mass-separated W n clusters cooled in a seeding gas are recorded with a low laser flux that ensures single-photon events. The spectra exhibit (i) sharp features due to direct photoemission and (ii) a broad emission signal whose intensity decreases with increasing kinetic energy. The latter is caused by delayed electron emission, a process similar to bulk 'thermionic emission'. The kinetic energy distribution of these electrons can be approximated by a Boltzmann function with a temperature corresponding to the photon energy divided by the number of vibrational degrees of freedom of the cluster.