Regensburg 2019 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 27: Focus Session: Designer Quantum Systems I (joint session O/TT)
TT 27.5: Talk
Tuesday, April 2, 2019, 12:00–12:15, H15
Eu-doped NaI scintillators: Point defects and EuI2 sheets. — •Martin Setvin1, Manuel Ulreich1, Igor Sokolovic1, Michele Reticcioli3, Lynn Boatner2, Flora Poelzleitner1, Cesare Franchini3, Michael Schmid1, and Ulrike Diebold1 — 1Institute of Applied Physics, TU Wien, Vienna, 1040, Austria — 2Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, 37831, USA — 3Faculty of Physics and Center for Computational Materials Science, University of Vienna, Vienna, Austria
Activator impurities and their distribution in the host lattice play a key role in scintillation phenomena. A combination of cross-sectional noncontact atomic force microscopy (nc-AFM) and X-ray photoelectron spectroscopy (XPS) was used to study the distribution of Eu2+ dopants in a NaI scintillator activated by 3% of EuI2. Two types of precipitate structures were identified. First, a single-sheet of EuI2 layered precipitate is a favoured configuration at the surface. Second, precipitates with a cubic crystal structure and a size below 4 nm were found in the bulk material. A surprisingly low concentration of point defects was detected in all of the investigated samples. The relation between the atomic structure and scintillation will be discussed.
The work was supported by the FWF Wittgenstein Prize Z-250.