Elastic scattering of low-energy electrons by carbon, silicon, germanium and tin tetrahalides

Abstract

In this paper we present cross sections for elastic scattering of low-energy electrons by carbon, germanium and tin tetrahalides, namely CBr4, CI4, GeBr4, GeI4, SnCl4, SnBr4 and SnI4. We also present previously published results for CCl4, SiCl4, SiBr4, SiI4 and GeCl4. Our calculations employed the Schwinger multichannel method with pseudopotentials at the fixed-nuclei static-exchange approximation. We have made a comparative study of the scattering cross sections of the above molecules, which have the same number of valence electrons. We also show the symmetry decomposition of the integral cross section according to the Td group for each one of the above molecules. We have found that the cross section for a given representation of the Td group presents the same pattern for all studied carbon, silicon, germanium, and tin tetrahalides. We have also calculated total ionization cross sections for these tetrahalides using the binary-encounter-Bethe model.

Elastic collisions of low-energy electrons with SiY4(Y=Cl, Br, I) molecules

“…Rotational excitation cross sections were also reported [9,10]. In another study we investigated, also in the SE approximation, the role of the peripheral and central atoms in electron collisions with carbon, silicon, germanium, and thin tetrahalides [11]. In particular, a series of shape resonances were found in the cross sections of the SiY 4 (Y = Cl, Br, I) belonging to the A 1 , T 2 , and E symmetries of the T d group, for SiCl 4 and SiBr 4 , and for T 2 and E symmetries of the T d group for SiI 4 .…”

Negative ion formation through dissociative electron attachment to the group IV tetrachlorides: Carbon tetrachloride, silicon tetrachloride and germanium tetrachloride

“…differential scattering cross sections by Azevedo et al [36] (0 to 30 eV), Joucoski and Bettega [93] (5-40 eV) and by Mozejko et al [82] (20 to 2000 eV) as well as the total inelastic and ionization cross sections recently reported by Verma et al [84] for the range from the ionization threshold to 5000 eV. The first two studies of the elastic cross sections employ the Schwinger Multichannel method, the third uses the independent atom model with a static-polarization model potential, while as noted previously the total inelastic cross sections reported by Verma et al [84] are computed using a spherical complex optical potential formalism.…”