Department of Surface Processes
The why? The how? The what?
The ultimate goal of our research, driven by scientific curiosity, is to gain fundamental and independent knowledge of the (geo)chemistry and environmental fate of long-lived radionuclides (RNs). One prominent and socially important application is the safe disposal of radioactive waste, to aid future generations in the responsibility of dealing with “our” legacy from energy production in nuclear reactors.
For this purpose we provide the radiochemical knowledge, namely structural and mechanistic data of important mobilizing and immobilizing reactions of RNs in solution, at interfaces, and in solids.
Our particular focus is using a variety of established and advanced microscopic and spectroscopic techniques, to accurately describe complex formation reactions and complex structures that govern RN interactions in the geosphere. In addition, we investigate the creation and chemical speciation of activation products in materials from nuclear power plants in the context of their safe decommissioning.
As part of a value chain, the derived structural information forms a sound basis for a reliable thermodynamic description of the investigated systems, which can be integrated in thermodynamic databases. The thermodynamic work is done in close collaboration with the department of Actinide thermodynamics.
Our core competencies
- Chemistry of long-lived RNs – Expertise in handling RNs, ranging from fission- and activation products to transuranium elements, and access to radiation safety labs.
- Structural characterization – Expertise in applying and coupling spectroscopic and microscopic as well as diffraction techniques for accessing molecular information.
- Thermodynamic description of RN complexes – Using macroscopic, spectroscopic, and calorimetric information of reactant-water-surface phenomena as basis for the derivation of surface complexation models and their thermodynamic parameters.
Research fields
- Coordination chemistry of RNs in aqueous solution and in human artificial biofluids.
- Molecular characterization of RN reactions at natural and engineered mineral-water interfaces, e.g. REDOX and RULET project.
- Environmental technetium chemistry., e.g. Young Investigator Group TecRad.
- Experimental support for calculations of neutron fields and the resulting activities close to nuclear reactors, e.g. EBENE project.
Latest Publication
Exploring metastable phases in cerium-doped zirconia: Insights from X-ray diffraction, Raman and Luminescence spectroscopy
Braga Ferreira dos Santos, L.; Svitlyk, V.; Richter, S.; Hennig, C.; Müller, K.; Bazarkina, E.; Kvashnina, K.; Stumpf, T.; Huittinen, N. M.
Abstract
The ZrO2-CeO2 system is crucial for various applications, but discrepancies persist regarding the miscibility of the cations and the occurrence of metastable phases in the Zr1-xCexO2 phase diagram. This work aimed to close these knowledge gaps by conducting detailed investigations of Zr1-xCexO2 compositions with varying cerium concentrations and incorporating Eu3+ as a luminescent probe. Synchrotron powder X-ray diffraction analysis revealed a miscibility gap between 20 and 50 mol% cerium, where two stoichiometric Zro.80Ce0.20O2 and Zro.50Ceo.50O2 phases coexist. Outside of this miscibility gap, solid solutions were found and various crystalline phases were identified, including monoclinic (m), tetragonal (t), tetragonal prime (t’), tetragonal double prime (t’’), and cubic (c), depending on the cerium concentration. The existence of the t’ and t’’ phases was confirmed through normalized lattice parameter an, and z(O) coordinates. Raman investigations revealed a distinct distortion band in all compositions containing the t’ phase. Contrary to existing literature, the HERFD-XANES demonstrated that the presence of the feature associated with distortion in Raman spectroscopy is not related to Ce3+, but is likely a result of the oxygen displacement in the t’ structure. Finally, luminescence spectroscopy of the europium environment in the samples revealed distinct excitation and emission spectra across the various crystal phases, enabling the unambiguous distinction of the metastable phases for the first time. This study reveals the complex binary ZrO2-CeO2 system, with several structural polymorphs. The ability to precisely control the phase composition offers immense potential for tuning the properties for different applications, such as in the SOFCs fields.
Keywords: ZrO2-CeO2 solid solutions; miscibility gap; D-band; tetragonal metastable phase; relative symmetry
Involved research facilities
- Rossendorf Beamline at ESRF DOI: 10.1107/S1600577520014265
Related publications
- DOI: 10.1107/S1600577520014265 is cited by this (Id 40057) publication
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Journal of the American Chemical Society 64(2025)19, 9670-9683
DOI: 10.1021/acs.inorgchem.5c00865
Permalink: https://www.hzdr.de/publications/Publ-40057
A list of publications can be found here.
Research groups
Currently running third-party funded projects
- Experimentally supported calculations of neutron fields and the resulting activities in spaces far from the reactor (EBENE) started: 04/2024, BMBF
- Interactions of technetium with microorganisms, metabolites and at the mineral-water interface – Radioecological considerations (TecRad) started: 07/2022, BMBF
- Redox reactivity of selenium in environmental geomedia (REDOX) started: 06/2022, ANDRA
- Retention and solubility of dose-relevant radionuclides under the reducing near-field conditions of a repository in clay or crystalline rock (RULET) started 11/2024, BMUV
An overview of finished projects can be found here.
Team
"Surface processes" department
Surface Processes
Head | |||||
Name | Bld./Office | +49 351 260 | |||
---|---|---|---|---|---|
Dr. Katharina Müller | 801/P248 | 2439 | k.mueller![]() | ||
Employees | |||||
Name | Bld./Office | +49 351 260 | |||
Dr. Astrid Barkleit | 801/P207 | 3136 2512 2518 | a.barkleit![]() | ||
Aline Chlupka | 801/P203 | 3198 2518 2523 | a.chlupka![]() | ||
Jiyoung Eum | j.eum![]() | ||||
Sebastian Friedrich | 801/P352 | 3154 | s.friedrich![]() | ||
Dr. Norbert Jordan | 801/P218 | 2148 | n.jordan![]() | ||
Stephan Weiß | 801/P316 | 2758 2523 | s.weiss![]() | ||
Maud Emilie Zilbermann | 801/P254 | 3487 | m.zilbermann![]() | ||
"TecRad" Wechselwirkung von Technetium mit Mikroorganismen, Metaboliten und an Mineral-Wasser-Grenzflächen - Radioökologische Betrachtungen | |||||
Name | Bld./Office | +49 351 260 | |||
Dr. Natalia Mayordomo Herranz | 801/P252 | 2076 | n.mayordomo-herranz![]() | ||
Caroline Börner | 801/P254 | 2251 | c.boerner![]() | ||
Arkadz Bureika | 801/P201 | 2434 | a.bureika![]() | ||
Irene Cardaio | 801/P254 | 2251 | i.cardaio![]() | ||
Dr. Marcos Felipe Martinez Moreno | 801/P352 | 3154 | m.martinez-moreno![]() | ||
Vijay Kumar Saini | 801/P352 | 3328 | v.saini![]() |
Alumni
Name | at HZDR |
---|---|
Heidrun Neubert | Lab assistant |
Sara E. Gilson | PostDoc |
Christa Müller | Lab assistant |
Quirina Isabella Roode-Gutzmer | Ph.D. student |
Isabelle Jessat | Ph.D. student, gratuated 2023 |
Maximilian Demnitz | Ph.D. student, graduated 2022 |
Diana Marcela Rodriguez Hernandez | Ph.D. student, graduated 2021 |
Henry Lösch | Ph.D. student, graduated 2021 |
Manuel Eibl | Ph.D. student, graduated 2020 |
Susanne Lehmann | Ph.D. student, graduated 2020 |