EGAS41 - Swansea University

41 st EGAS CP 67 Gdańsk 2009
Electron collisions with Pt(PF 3 ) 4
M. Allan
Department of Chemistry, University of Fribourg, chemin du Musée 9, 1700 Fribourg,
Switzerland
E-mail: michael.allan@unifr.ch,
The interest in electron interactions with Pt(PF 3 ) 4 stems from its use as a platinum
precursor in Focused Electron Beam Induced Processing (FEBIP) [1]. It is a volatile
platinum compound with a molar mass of 547 amu! For FEBIP it has the advantage of
not causing carbon deposits. It is a tetrahedral d 10 complex.
Representative vibrational energy-loss spectrum, recorded with about 10 meV resolution
at an incident energy of 0.7 eV is shown in Fig. 1, with an assignment based on the
vibrational frequencies from Ref. [2]. Cross sections were measured for elastic scattering
and for vibrational and electronic excitation, both as a function of electron energy and as
a function of scattering angle. The elastic cross sections have deep Ramsauer-Townsend
minima and their angular distributions have interesting minima around 40 ◦ which drop
to lower scattering angles with increasing energy. The cross sections for vibrational excitation,
reveal five resonances, probably shape resonances.
2
Cross Section (Å /sr)
4
3
2
1
0
Pt(PF ) 3 4
×1
1 PF str
2 PF 3 deform
16 PF 3 asym deform
3 Pt-P str
0.0 0.2 0.4
Energy Loss (eV)
×20
×4
Figure 1: Electron energy-loss spectrum of Pt(PF 3 ) 4 , recorded with an incident electron energy
of 0.7 eV at a scattering angle of 45 ◦ .
References
[1] I. Utke, P. Hoffmann, J. Melngailis, J. Vac. Sci. Technol. B 26, 1197 (2008)
[2] R.M. Blight-Smith, H.G.M. Edwards, V. Fawcet, Spectrochim Acta 43A, 1069 (1987)
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