Université de Fribourg

Dissociative electron attachment and electronic excitation in Fe(CO)5

Allan, Michael ; Lacko, M. ; Papp, P. ; Matejčík, Š. ; Zlatar, Matija ; Fabrikant, Ilya I. ; Kočišek, J. ; Fedor, Juraj

In: Physical Chemistry Chemical Physics, 2018, vol. 20, no. 17, p. 11692–11701

In a combined experimental and theoretical study we characterize dissociative electron attachment (DEA) to, and electronically excited states of, Fe(CO)5. Both are relevant for electron-induced degradation of Fe(CO)5. The strongest DEA channel is cleavage of one metal–ligand bond that leads to production of Fe(CO)4−. High- resolution spectra of Fe(CO)4− reveal fine structures at the...

Université de Fribourg

Long-lived transient anion of c-C₄F₈O

Kočišek, J. ; Janečková, Radmila ; Fedor, Juraj

In: The Journal of Chemical Physics, 2018, vol. 148, no. 7, p. 074303

We report partial cross sections for electron attachment to c-C4F8O, a gas with promising technological applications in free-electron-rich environments. The dissociative electron attachment leads to a number of anionic fragments resulting from complex bond-breaking and bond-forming processes. However, the anion with the highest abundance is the non-dissociated (transient) parent anion which...

Université de Fribourg

Electron attachment properties of c-C₄F₈O in different environments

Chachereau, A. ; Fedor, Juraj ; Janečková, Radmila ; Kočišek, J. ; Rabie, M. ; Franck, C. M.

In: Journal of Physics D: Applied Physics, 2016, vol. 49, no. 37, p. 375201

The electron attachment properties of octafluorotetrahydrofuran (c-C₄F₈O) are investigated using two complementary experimental setups. The attachment and ionization cross sections of c-C₄F₈O are measured using an electron beam experiment. The effective ionization rate coefficient, electron drift velocity and electron diffusion coefficient in c-C₄F₈O diluted to concentrations...

Université de Fribourg

Growth of ice nanoparticles via uptake of individual molecules: pickup cross sections

Fedor, Juraj ; Lengyel, Jozef ; Kočišek, J. ; Poterya, V. ; Pysanenko, A. ; Svrčková, P. ; Fárník, M.

In: Journal of Physics: Conference Series, 2014, vol. 488, no. 10, p. 102016

We present cross sections for pickup of several atmospherically relevant molecules on ice nanoparticles with the 0.5-3 nm diameter range. The experimental values are supported by molecular dynamics simulations and analytical calculations based on long-range cluster-molecule potentials. The cross sections are all considerably larger than the geometrical cross section of nanoparticle and vary...

Université de Fribourg

Electron impact excitation of methane: determination of appearance energies for dissociation products

Danko, M. ; Orszagh, J. ; Ďurian, M. ; Kočišek, J. ; Daxner, M. ; Zöttl, S. ; Maljković, J. B. ; Fedor, Juraj ; Scheier, P. ; Denifl, S. ; Matejčík, Š.

In: Journal of Physics B: Atomic, Molecular and Optical Physics, 2013, vol. 46, no. 4, p. 045203

In this work, we present an experimental study of dissociative excitation of CH₄ utilizing a crossed electron molecular beam experiment. Methane was excited by nearly monochromatic electrons generated by a trochoidal electron monochromator. The dissociative products were identified on the basis of the emission spectra in the ultraviolet–visible (UV/VIS) spectral range. The excitation...

Université de Fribourg

Uptake of atmospheric molecules by ice nanoparticles: Pickup cross sections

Lengyel, J. ; Kočišek, J. ; Poterya, V. ; Pysanenko, A. ; Svrčková, P. ; Fárník, M. ; Zaouris, D. K. ; Fedor, Juraj

In: Journal of Chemical Physics, 2012, vol. 137, p. 034304

Uptake of several atmospheric molecules on free ice nanoparticles was investigated. Typical examples were chosen: water, methane, NOx species (NO, NO₂), hydrogen halides (HCl, HBr), and volatile organic compounds (CH₃OH, CH₃CH₂OH). The cross sections for pickup of these molecules on ice nanoparticles (H₂O)N with the mean size of ***Missing image...