Laboratory for applied X-ray spectroscopy

Jožef Stefan Institute,
Jamova 39,
SI-1000 Ljubljana,
Slovenia


Leader: Dr Matjaž KavčičCoworkers: Dr Marko Petric, Doc. Dr Klemen Bučar, Kristina Isaković

Activities

Experimental studies of fundamental properties of atoms and molecules

Synchrotron radiation-based X-ray spectroscopic techniques are used to study fundamental properties of isolated atoms and molecules. Our main experimental technique is Resonant Inelastic X-ray Scattering (RIXS). In RIXS experiment the incident energy is tuned to a corresponding absorption edge and the subsequent radiative decay is recorded using the emission spectrometer with energy resolution comparable to the resolution of the beamline monochromator and preferably smaller than the lifetime broadening of the spectral features. Several RIXS/XES experimental campaigns at different synchrotrons have been performed in recent years using our tender x-ray emission spectrometer. We have successfully studied multielectron atomic excitations and also structural and dynamic properties of different molecules.

Important publications:

 

Electronic structure and chemical speciation studies of different materials

X-ray spectroscopy is employed in different analytical techniques used to study electronic structure of atoms in complex materials. Our tender x-ray emission spectrometer has been used extensively in electronic structure studies of different solid and also liquid materials. In collaboration with the group for Modern Battery Systems at our National Institute of Chemistry, RIXS spectroscopy has been introduced as a powerful tool used to study electrochemical processes in energy storage materials, especially sulfur-based batteries. In addition, the high-energy resolution X-ray emission spectroscopy (XES) method is also successfully combined with MeV proton beam excitation in order to extend the analytical capabilities of standard PIXE technique towards chemical speciation.

Important publications:

 

Inner-shell ionization induced in ion-atom collisions

Atomic inner-shell ionization studies are performed within our home laboratory using MeV ion beams accelerated with the 2 MV Tandem ion accelerator. High energy resolution detection of ion induced x-ray emission is used to resolve contributions from different inner-shell vacancy configurations produced in the collision. This approach is used to study multiple inner-shell ionization induced in such collisions. High-energy resolution was also used to separate spectral contributions originating from different atomic subshells and determine precisely their ionization cross section ratio as a function of ion impact energy.

Important publications:

Laboratory for applied x-ray spectroscopy is a part of a broader research program P1-0112 (Research of atoms molecules and structures with photons and particles) and covers research field based on the use of high energy resolution x-ray spectroscopy. The main experimental tool represents a home built x-ray emission spectrometer for high energy resolution spectroscopy in the “tender” x-ray range (~2-5 keV). The main purpose of the laboratory is development of advanced x-ray spectroscopic tools and methods and their application in fundamental research in atomic and molecular physics as well as interdisciplinary research mainly in the development of new technologically relevant materials. Part of the laboratory activities represents experimental work involving synchrotron radiation going on at different synchrotron facilities across Europe. Second part represents development and applications of analytical methods based on ion induced X-ray emission and is going on within home laboratory at IJS. The laboratory collaborates successfully with different foreign and domestic research groups. from abroad and also from Slovenia. We can point out very fruitful cooperation with the group from synchrotron ESRF in Grenoble and the group for Modern battery systems from the Chemical Institute in Ljubljana. We are actively involved in the international initiative for the development of lab based X-ray absorption/emission spectroscopy employing laboratory sources.