ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Penning ionization electron spectra (PIES) of van der Waals clusters have been observed for the first time by means of a newly developed magnetic bottle electron spectrometer, which is 1000 times more efficient than a conventional PIES apparatus. In the PIES of Ar clusters with He*(2 3S), two bands of Ar 3p hole characters with different ionization energies (IE), band A (IE=ca.15 eV) and band B (IE=ca.13.5 eV), were observed. Band A was assigned to vertical transitions in Franck–Condon regions corresponding to the band in the ultraviolet photoelectron spectra (UPS) of clusters reported by Carnovale et al. [J. Chem. Phys. 90, 1452 (1989)]. Band B, which is an extra band missing in the UPS of clusters, can be ascribed to the autoionization into a stable structure of Arn+ via superexcited states of Arn. Band B can be considered as an adiabatic ionization which is forbidden as a direct ionization. The energy difference of ca. 1.5 eV between the vertical IE for band A and the adiabatic IE for band B was found to agree well with the reported binding energy of the trimer ion core. © 2000 American Institute of Physics.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.481303
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