Elastic differential cross sections for C4F6 isomers in the 1.5–200 eV energy electron impact: Similarities with six fluorine containing molecules and evidence of F-atom like scattering

Abstract

We report absolute elastic differential cross sections for electron interactions with the C 4 F 6 isomers, hexafluoro-1,3-butadiene (1,3-C 4 F 6 ), hexafluoro-2-butyne (2-C 4 F 6 ), and hexafluorocyclobutene (c-C 4 F 6 ). The incident electron energy range is 1.5-200 eV, and the scattered electron angular range for the differential measurements varies from 15 • to 150 • . In all cases the absolute scale of the differential cross section was set using the relative flow technique, with helium as the reference species. Atomic-like behaviour in these scattering systems is shown here for the first time, and is further investigated by comparing the elastic cross sections for the C 4 F 6 isomers with other fluorinated molecules, such as SF 6 and C n F 6 (n = 2, 3, and 6). We note that for all the six-F containing molecules, the scattering process for electron energies above 30 eV is indistinguishable. Finally, we report results for calculations of elastic differential cross sections for electron scattering from each of these isomers, within an optical potential method and assuming a screened corrected independent atom representation. The level of agreement between these calculations and our measurements is found to be quite remarkable in all cases.

Absolute cross section measurements for the scattering of low- and intermediate-energy electrons from PF3. I. Elastic scattering

“…Hence, we explore the systematics of the elastic DCSs for the four-atom trifluoride, XF 3 (X = B, N, and P) molecules in a similar way as that discussed in our previous series of studies. 1,[10][11][12][13] The present comparison shows that these elastic DCSs are independent of the nature of the central X atoms at the vertex of XF 3 (X = B, N, and P) above 30 eV, while their own chemical and physical properties begin to emerge clearly in the DCSs below 10 eV. Finally, TCS values have also been estimated by adding the total inelastic cross sections calculated by the IAM-SCAR and the measured vibrational inelastic cross sections (see Ref.…”

Crossed-beam experiment for the scattering of low- and intermediate-energy electrons from BF3: A comparative study with XF3 (X = C, N, and CH) molecules

“…[25][26][27][28][29]. Briefly, each atomic target (B, F) is represented by an interacting complex potential (the so-called optical potential).…”

“…Similar behavior has been observed for the case of CCl 4 , 25 YF 4 (Y = C, Si, and Ge), 27 COS and CS 2 , 28 and recently in C n F 6 molecules (n = 2, 3, 4, and 6). 29 For these molecular systems, the central atoms are lighter than the outer atomic system. However, in the case of YH 4 (Y = C, 47 Si, 48 and Ge 49 ) molecules, the structure in the angular distributions was partly found in the corresponding noble gas species (Ne, Ar, Kr, and Xe atom).…”

Theoretical and experimental study on electron interactions with chlorobenzene: Shape resonances and differential cross sections

“…[38][39][40][41][42] Briefly, each atomic target (C, Cl, H) is represented by an interacting complex potential, the so-called optical potential. The real part accounts for the elastic scattering of the incident electrons, and the imaginary part represents the inelastic processes, which is considered as "absorption" from the incident beam.…”