Repository of University of Nova Gorica

Show document
A+ | A- | Help | SLO | ENG

Title:K-edge absorption spectra of gaseous hydrides
Authors:ID Kodre, Alojz, Univerza v Ljubljani (Author)
ID Hauko, Robert, Univerza v Mariboru (Author)
ID Padežnik Gomilšek, Jana, Univerza v Mariboru (Author)
ID Arčon, Iztok, UNG (Author)
ID Aquilanti, Giuliana, Elettra (Author)
Files: This document has no files that are freely available to the public. This document may have a physical copy in the library of the organization, check the status via COBISS. Link is opened in a new window
Language:English
Work type:Not categorized
Typology:1.12 - Published Scientific Conference Contribution Abstract
Organization:UNG - University of Nova Gorica
Abstract:X-ray absorption spectra in the energy region of absorption edges reveal fine details of the mechanism of inner-shell photoexcitation: in particular in spectra of free atoms or simple molecules, the simplest being gaseous hydrides [1-2]. In a collection of data from consecutive and homologous elements, analyzed by a common procedure, the reaction channels can be identified with better precision and reliability than in analysis of individual spectra. Absorption spectra of the hydrides of 3p elements (PH3, H2S in HCl) were measured at the XAFS beamline of the Elettra synchrotron in Trieste: a new type of adjustable absorption cell for measurement of noxious gases at room temperature and at low photon energies was developed for the purpose. For the analysis, data from an earlier experiment on 4p hydrides (GeH4, AsH3, H2Se, HBr), and published data of 2p hydrides (CH4, NH3, H2O, HF) [3-4] as well as SiH4 and the noble gases concluding the isoelectronic series (Ne, Ar, Kr) were adopted. The spectra are compared to respective calculated spectra, obtained by atomic HF86, GRASP codes and molecular DFT (Density functional theory) ORCA code [5]. Our analysis of the pre-edge structures showed that the energies and probabilities of singleelectron transitions into the lowermost orbitals with the molecular character were strongly affected by the symmetry of the molecule, essentially in the same way in 3p and 4p homologues, but not in 2p homologues with a stronger influence of the core charge. In transitions to higher orbitals with prevailing atomic character the influence of the molecular field is negligible. The fine structure immediately above the K edge stems from the coexcitation of valence electrons. These coexcitations can be explained as a two-step process: the inner-shell photoeffect followed by the shake-up of a valence electron predominantly to a free atomic orbital. The process is markedly different from coexcitations of more tightly bound electrons [3]. The results of relative shake-up probabilities can be compared to results of emission spectroscopies, the probabilities of double excitation to bound states show a correlation with the dissociation probability of the molecule.
Keywords:večelektronske vzbuditve, hidridi, rentgenska absorpcijska spektroskopija
Year of publishing:2018
Number of pages:1
PID:20.500.12556/RUNG-4271 New window
COBISS.SI-ID:5220091 New window
NUK URN:URN:SI:UNG:REP:VPDPJTBZ
Publication date in RUNG:12.09.2018
Views:5703
Downloads:0
Metadata:XML DC-XML DC-RDF
:
KODRE, Alojz, HAUKO, Robert, PADEŽNIK GOMILŠEK, Jana, ARČON, Iztok and AQUILANTI, Giuliana, 2018, K-edge absorption spectra of gaseous hydrides. In : Book of abstracts, European Conference on X-Ray Spectrometry - EXRS-2018 [online]. Published Scientific Conference Contribution Abstract. Ljubljana. 2018. [Accessed 21 April 2025]. Retrieved from: https://repozitorij.ung.si/IzpisGradiva.php?lang=eng&id=4076
Copy citation
  
Average score:
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
(0 votes)
Your score:Voting is allowed only for logged in users.
Share:Bookmark and Share


Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Record is a part of a monograph

Title:Book of abstracts, European Conference on X-Ray Spectrometry - EXRS-2018
Editors:Matjaž Kavčič
Place of publishing:Ljubljana
Publisher:Inštitut Jožef Stefan
Year of publishing:2018
ISBN:978-961-264-126-9
Conference organizer:Inštitut Jožef Stefan

Back