https://doi.org/10.1007/s100530050545
Photo-atomic effect: Temperature dependence of the photodesorption of Na and Na2 from polymer surfaces
1
Scuola Normale Superiore and INFM, Piazza dei Cavalieri 7,
56100 Pisa, Italy
2
INFM and Department of Physics,
Via F. Buonarroti 2, 56100 Pisa, Italy
3
Department of Chemistry, The Pennsylvania State University,
152 Davey Laboratory, University Park, PA 16802, USA
Received:
23
April
1999
Revised:
15
July
1999
Published online: 15 May 2000
Alkali metals adsorbed to surface films of the polymer poydimethylsiloxane (PDMS)
have been shown to exhibit a unique photodesorption behavior, characterized by a
frequency threshold and high efficiency. In this work, the temperature dependence
of the photodesorption yields of Na and 
from PDMS surfaces were
measured between room temperature and 183 K. Over most of the temperature range,
the yields exhibited an Arrhenius behavior characterized by thermal activation
energies of 0.36 eV and 0.34 eV for Na and , respectively. These
values are suggestive of a surface diffusion as one of the elementary steps in the
photodesorption mechanism. Moreover, the similarity of the two values indicates
that the same elementary step applies to the desorption of both Na and .
PACS: 34.50.Dy – Interactions of atoms, molecules, and their ions with surfaces; photon and electron emission; neutralization of ions / 79.20.La – Photon- and electron-stimulated desorption
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000
