Absolute cross section measurements for the scattering of low- and intermediate-energy electrons from PF3. II. Inelastic scattering of vibrational and electronic excitations

Abstract

As a sequel paper to our study of the elastic scattering for electron collisions with phosphorus trifluoride, PF molecules, we report absolute inelastic differential and integral cross sections (DCS and ICS) of vibrational excitations for the compound fundamental vibrational modes v (v + v), v (v + v), and their sum in the impact energy range of 2.0-10 eV and over a scattering angle range of 20°-130°. The measured angular distributions of scattered electron intensities for the present inelastic scattering are normalized to the elastic peak intensity corresponding to the DCSs of He. These vibrational excitation measurements demonstrate the presence of resonances around 2 eV and also around 6-10 eV. In addition, a generalized oscillator strength analysis is applied to derive oscillator strength f-values and (unscaled Born) ICSs from the corresponding DCSs measured for the low-lying optically allowed 8a → 7e (σ*) excitation band, which is assigned as the Jahn-Teller splitting and 8a → 4s Rydberg transition at impact energies of 100, 200, and 300 eV, over a scattering angle range of 1.0°-15°. The f-values obtained in the present study are compared with the results of previous photoabsorption and pseudo-optical measurements. The unscaled Born ICSs are compared with the binary-encounter f-scaled Born ICSs estimated over a wide impact energy region from the excitation thresholds.

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

“…Details on inelastic processes, especially vibrational and electronic excitations, for the e + PF 3 collisional system will be discussed in a sequel paper (Part II). 14…”

Ionisation of PF3: absolute partial electron ionisation cross sections and the formation and reactivity of dication states

“…Previous studies of electron scattering from PF 3 have included the calculation of the total elastic and total inelastic (ionisation and excitation) cross sections (0.15 to 5000 eV), 23 measurement and calculation of elastic differential cross sections between 2.0-200 eV, 24 measurement and calculation of integral and differential vibrational cross sections (2.0-10 eV), 25 measurement of ion appearance energies and relative ion intensities at 70 eV, 26,27 measurement of experimental absolute total scattering cross sections (0.5 to 370 eV) 28 and calculations of partial differential ionisation cross sections at 100 eV and 200 eV. 29 Photoionisation of PF 3 has also been investigated.…”

The infrared spectrum of PF3and analysis of rotational energy clustering effect

“…The microwave rotational spectrum has also been rather well studied [17,27,[33][34][35][36]. Very recently a study of vibrational and electronic inelastic electron scattering on PF 3 has been reported [37].…”