Collisional relaxation of metastable electronic states of Fe<sup>+</sup>

Russell, David H.; Solouki, Touradj; Oriedo, J. V. B.

doi:10.1016/1044-0305(95)00233-4

Cited by 10 publications

(7 citation statements)

References 29 publications

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“…Indeed, the depopulation of the Fe 4s orbital observed for the Fe x O x+1 molecules when compared to Fe x O x correlates with the decreasing discrepancy between the methods when increasing the number of oxygen atoms in the respective molecule. The substantial depopulation of the Fe 4s orbital in the oxides compared to atomic iron may underlie also the fact that the DM cross sections for FeO and FeO 2 are smaller than the EICS of atomic iron [69], although the ionisation thresholds are not much different (7.92 eV for atomic iron [70] [22]. Overall, our results are in line with the interpretation given for this discrepancy in reference [22].…”

Section: Electron Impact Ionisation Cross Sectionssupporting

confidence: 82%

Electron impact ionisation cross sections of iron oxides

et al. 2017

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Abstract. We report electron impact ionisation cross sections (EICSs) of iron oxide molecules, FexOx and FexOx+1 with x = 1, 2, 3, from the ionisation threshold to 10 keV, obtained with the Deutsch-Märk (DM) and binary-encounter-Bethe (BEB) methods. The maxima of the EICSs range from 3.10 to 9.96 × 10 −16 cm 2 located at 59-72 eV and 5.06 to 14.32 × 10 −16 cm 2 located at 85-108 eV for the DM and BEB approaches, respectively. The orbital and kinetic energies required for the BEB method are obtained by employing effective core potentials for the inner core electrons in the quantum chemical calculations. The BEB cross sections are 1.4-1.7 times larger than the DM cross sections which can be related to the decreasing population of the Fe 4s orbitals upon addition of oxygen atoms, together with the different methodological foundations of the two methods. Both the DM and BEB cross sections can be fitted excellently to a simple analytical expression used in modelling and simulation codes employed in the framework of nuclear fusion research.

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Section: Electron Impact Ionisation Cross Sectionssupporting

confidence: 82%

Electron impact ionisation cross sections of iron oxides

et al. 2017

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“…In order for the experiment to distinguish the reactivity of the two states, the quenching rate for 4 Fe + to 6 Fe + by He must be comparable or slower than the reaction time. Oriedo et al 26 have studied collisional relaxation of exited states of Fe + with numerous collision partners. They found 4 Fe + to be poorly quenched relative to other excited states, especially by He.…”

Section: Resultsmentioning

confidence: 99%

Spin-inversion and spin-selection in the reactions FeO⁺ + H₂ and Fe⁺ + N₂O

Ard

Johnson

Melko

et al. 2015

Phys. Chem. Chem. Phys.

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The reactions of FeO(+) with H2 and of Fe(+) with N2O were studied with respect to the production and reactivity of electronically excited (4)Fe(+) cations. The reaction of electronic ground state (6)FeO(+) with H2 was found to predominantly produce electronically excited (4)Fe(+) as opposed to electronic ground state (6)Fe(+) corresponding to a spin-allowed reaction. (4)Fe(+) was observed to react with N2O with a rate constant of 2.3 (+0.3/-0.8) × 10(-11) cm(3) molecule(-1) s(-1), smaller than the ground state (6)Fe(+) rate constant of 3.2 (±0.5) × 10(-11) cm(3) molecule(-1) s(-1) (at room temperature). While the overall reaction of (6)FeO(+) with H2 within the Two-State-Reactivity concept is governed by efficient sextet-quartet spin-inversion in the initial reaction complex, the observation of predominant (4)Fe(+) production in the reaction is attributed to a much less efficient quartet-sextet back-inversion in the final reaction complex. Average spin-inversion probabilities are estimated by statistical modeling of spin-inversion processes and related to the properties of spin-orbit coupling along the reaction coordinate. The reaction of FeO(+) with H2 served as a source for (4)Fe(+), subsequently reacting with N2O. The measured rate constant has allowed for a more detailed understanding of the ground state (6)Fe(+) reaction with N2O, leading to a significantly improved statistical modeling of the previously measured temperature dependence of the reaction. In particular, evidence for the participation of electronically excited states of the reaction complex was found. Deexcitation of (4)Fe(+) by He was found to be slow, with a rate constant <3 × 10(-14) cm(3) molecule(-1) s(-1).

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“…2) as the latter shows a non-zero cross section below the ionisation energy of iron in its electronic ground state, i.e. 7.92 eV [61]. The substantially higher maximum of 5.34 × 10 −16 cm 2 at 29 eV in the latter cross section [61] is also an indication that this cross section includes contributions from the ionisation of excited metastable iron [62].…”

Section: Eics Of Fementioning

confidence: 90%

“…7.92 eV [61]. The substantially higher maximum of 5.34 × 10 −16 cm 2 at 29 eV in the latter cross section [61] is also an indication that this cross section includes contributions from the ionisation of excited metastable iron [62]. There is a slight difference between our DM cross section and the one obtained by Deutsch et al [62], which yields a maximum of 4.59 × 10 −16 cm 2 at 25 eV and was also obtained using the DM formalism.…”

Section: Eics Of Fementioning

confidence: 99%

Electron impact ionisation cross sections of iron hydrogen clusters

et al. 2016

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Abstract.We computed electron impact ionisation cross sections (EICSs) of iron hydrogen clusters, FeHn with n = 1, 2, . . . , 10, from the ionisation threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. at 51 eV for the DM method. Cross sections calculated via the BEB method are substantially higher than the ones obtained via the DM method, up to a factor of about two for FeH and FeH2. The formation of Fe-H bonds depopulates the iron 4s orbital, causing significantly lower cross sections for the small iron hydrides compared to atomic iron. Both the DM and BEB cross sections can be fitted perfectly against a simple expression used in modelling and simulation codes in the framework of nuclear fusion research. The energetics of the iron hydrogen clusters change substantially when exact exchange is present in the density functional, while the cluster geometries do not depend on this choice.

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Collisional relaxation of metastable electronic states of Fe⁺

Cited by 10 publications

References 29 publications

Electron impact ionisation cross sections of iron oxides

Electron impact ionisation cross sections of iron oxides

Spin-inversion and spin-selection in the reactions FeO⁺ + H₂ and Fe⁺ + N₂O

Electron impact ionisation cross sections of iron hydrogen clusters

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Collisional relaxation of metastable electronic states of Fe+

Cited by 10 publications

References 29 publications

Electron impact ionisation cross sections of iron oxides

Electron impact ionisation cross sections of iron oxides

Spin-inversion and spin-selection in the reactions FeO+ + H2 and Fe+ + N2O

Electron impact ionisation cross sections of iron hydrogen clusters

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Collisional relaxation of metastable electronic states of Fe⁺

Spin-inversion and spin-selection in the reactions FeO⁺ + H₂ and Fe⁺ + N₂O