NUKFER

NUKFER is a joint research project for the development of novel sample environments for the investigation of iron-based materials using synchrotron radiation. The project covers the design and implementation of an experimental setup at the Dynamics beamline P01 at PETRA III dedicated to in situ nuclear resonant scattering experiments on individual nano-objects using nanofocused X-ray beam. The project is driven by scientists at the Laboratory for Applications of Synchrotron Radiation (LAS) (Laboratorium für Applikationen der Synchrotronstrahlung) that develops technologies and methods for the investigation of structural and functional relationships in biological systems, condensed matter and functional materials, using synchrotron radiation.

The aim of the project is to establish in situ nuclear resonant scattering using a nanofocused beam at the Dynamics beamline P01 of PETRA III. This will provide a a unique experimental technique for simultaneous determination of magnetism and lattice dynamics of individual Fe-based nano-objects.

Nuclear forward scattering and nuclear inelastic scattering are experimental methods based on the Mössbauer effect. In these experiments, highly monochromatized synchrotron radiation with energy matching the energy of the nuclear resonant transition (14.4 keV in the case of the Mössabuer isotope 57Fe) drives the nucleus into an excited state. After its mean lifetime the excited nucleus returns to the ground state by emitting either gamma-quanta with energy 14.4 keV, or conversion electron followed by fluorescent radiation. By detecting the gamma quanta emitted in forward direction (nuclear forward scattering) one can obtain information about the chemical state, electric and magnetic properties of the sample. By detecting the fluorescent radiation as a function of the energy transfer (nuclear inelastic scattering) one derives the phonon density of states and the relevant thermodynamic and elastic properties of the sample.

 

 

Schematic of the beamline & experimental setup at P01@PETRA: the beamline provides a highly monochromatized  (ΔE/E ≈1x10-7 at 14.4 keV) focused  beam between 5 and 70 keV with detectors for both forward and fluorescence scattering (-> link). 

The project, funded by the BMBF (05K16VK4), is proposed and entirely driven by IPS/LAS scientists Dr. S. Stankov and the PhD student J. Kalt.

Publications:

 

Lattice dynamics of epitaxial strain-free interfaces (-> link)

 

J. Kalt, M. Sternik, I. Sergueev, J. Herfort, B. Jenichen, H.-C. Wille, O. Sikora, P. Piekarz, K. Parlinski, T. Baumbach and S. Stankov Phys. Rev. B Rapid Communications 98, 121409(R) (2018)

 

See also EurekAlert! press release (-> link)

 

Ab initio and nuclear inelastic scattering studies of Fe3Si/GaAs heterostructures

 

O. Sikora, J. Kalt, M. Sternik, A. Ptok, P. T. Jochym, J. Łażewski, P. Piekarz, K. Parlinski, I. Sergueev, H.-C. Wille, J. Herfort, B. Jenichen, T. Baumbach, and S. Stankov (submitted to Phys. Rev. B)