The Disch Group studies order and disorder at different length scales in magnetic nanostructures.
A central challenge in this field is understanding how defects and disorder at surfaces and interfaces critically shape magnetic properties through structural relaxation at the nanoscale, and how this influences their behavior for biomedical or energy applications. Our long-term goal is an understanding of structure and magnetism from the atomic scale through nanoscale morphology to macroscopic applications, enabling the tailored design of functional materials. We address this using and developing novel X-ray and neutron scattering methods, combined with macroscopic magnetization measurements.
Magnetic Nanoparticles
Magnetic nanoparticles show rich relaxation behavior relevant to sensing, data storage, and biomedical applications such as hyperthermia.
Using magnetic small-angle neutron scattering, we map how magnetization is distributed within nanoparticles, and where and why spin disorder arises. Spin disorder often traces back to atomic-scale structural imperfections, leading to the growing recognition that defect engineering in magnetic nanoparticles holds great potential for improving magnetic heating performance. We also study the interactions that drive nanoparticles to self-organize into ordered assemblies, controlled by particle shape and applied magnetic fields. Much of this work builds on our previous Emmy Noether project on magnetization dynamics and directional anisotropy in magnetic nanostructures.
A. Lak, S. Disch, P. Bender 2021 Embracing Defects and Disorder in Magnetic nanoparticles
D. Zákutná, N. Rouzbeh, S. Disch et al. 2023 Magnetic coupling in Cobalt-Doped Iron Oxide Core-Shell nanoparticles: Exchange pinning through Epitaxial Alignment
E.L. Rösch, S. Disch, A. Lak et al. 2025 Origin of Wasp-Waisted Shape of Magnetization Hysteresis Loops in Co3O4 Nanoassemblies for Magnetic Hyperthermia
Nanostructured Electrode Materials
Batteries and catalysis are central to a sustainable energy future, and understanding how their nanostructure evolves during use is key to improving their performance.
Building on our Röntgen-Ångström Cluster collaboration nPDFSAS, we investigate oxide nanoparticles, such as magnetic ferrites, as electrode and catalyst materials. Using small- and wide-angle X-ray/neutron scattering under in-situ and operando conditions, we track how their structure and magnetism change under realistic reaction conditions, such as pyrolysis or electrochemical cycling. We will extend this approach to catalysis in aqueous environment as part of the ACTIVE SITES research initiative.
L. Rochels, S. Disch, et al. 2026 Influence of Anaerobic Pyrolysis on the Electrochemical Behavior of Mesocrystals
Microstructural Effects in Functional Materials
The performance of functional materials is strongly shaped by microstructural features such as grain boundaries, dislocations, texture and nanoscale phase separation, which in magnetic materials also drive spin disorder.
We combine magnetic small-angle neutron scattering with X-ray and neutron total scattering to connect atomic-scale order and disorder to microstructures, and ultimately to macroscopic performance, across a range of functional materials such as additively manufactured steels. Our work on permanent-magnet alloys is part of the collaborative research center HoMMage, which aims to develop new magnetic materials for efficient energy technologies.
Preprint: T, Tappe, L. Becker, G. Kanu, T.F. Headen, D. Honecker, G. Schierning, S. Benito, S. Weber, K. Lünser, S. Disch 2026 Impact of hydrogen incorporation on electronical and magnetic structure of X2CrNi8-9 stainless steel