Magnetic materials and crystal growth
Our Research
Complex metallic materials such as topological magnets, high-entropy alloys and quasicrystals exhibit unique structural properties that give rise to a variety of phenomena and effects. Often, these are not well understood but bear great potential for future application in fields such as electronics, energy systems, and quantum technology.
We employ advanced transmission electron microscopy to investigate structural, chemical, electronic and magnetic properties including in situ investigations using temperature and mechanical stimuli, electrical bias and optical illumination. For the understanding of subtle effects intrinsic to the materials, it is imperative to work on samples of highest structural purity and quality. To this end, we develop dedicated growth routes and utilize advanced single-crystal growth methods such as the Czochralski-, Bridgman and self-flux growth technique.
Research topics:
- Development of growth routes in multicomponent metallic systems
- Single-crystal and single-phase production of complex metallic alloys
- Quantitative magnetic imaging using Lorentz TEM, differential phase contrast imaging and electron holography
- In situ TEM investigations of functional properties
Points of contact
Dr. Michael Feuerbacher
Scientific staff at ER-C-1
- er-c
- er-c-1
Room 3075
Dr. Andras Kovacs
Scientific staff at ER-C-1
- er-c
- er-c-1
Room 3084
Publications
1. A. Kovács, N.B. Venkataraman, V. Chaudhary, S. Dasari, T. Denneulin, R.V. Ramanujan, R. Banerjee, R.E. Dunin-Borkowski, Role of heterophase interfaces on local coercivity mechanisms in the magnetic Al0.3CoFeNi complex concentrated alloy, Acta Materialia 246 (2023) 118672, doi: 10.1016/j.actamat.2023.118672
2. A. Kovács, N.B. Venkataraman, V. Chaudhary, S. Dasari, T. Denneulin, R.V. Ramanujan, R. Banerjee, R.E. Dunin-Borkowski, Role of heterophase interfaces on local coercivity mechanisms in the magnetic Al0.3CoFeNi complex concentrated alloy, Acta Materialia 246 (2023) 118672, doi: 10.1016/j.actamat.2023.118672
3. D. Kong, A. Kovács, M. Charilaou, F. Zheng, L. Wang, X. Han and R.E. Dunin-Borkowski, Direct observation of tensile-strain-induced nanoscale hardening, Nature Communications 14 (2023) 3963, doi: 10.1038/s41467-023-39650-8
4. M. Heggen, M. Feuerbacher, R.E. Dunin-Borkowski, Direct observation of dislocation motion in the complex alloy T-Al-Mn-Fe using in-situ transmission electron microscopy. Mat. Res. Lett. 11 (2022) 367 – 373, doi: 10.1080/21663831.2022.2155492
5. F. Zheng, F. N. Rybakov, N. S. Kiselev, D. Song, A. Kovács, H. Du, S. Blügel & R. E. Dunin-Borkowski, Magnetic skyrmion braids, Nature Communications 12, 5316 (2021). doi: 10.1038/s41467-021-25389-7
6. A. Kovács and R.E. Dunin-Borkowski, Chapter 2: Magnetic imaging of nanostructures using off-axis electron holography, in Handbook of Magnetic Materials, vol. 27 (2018) p. 59 (ed. E. Brück), doi: 10.1016/bs.hmm.2018.09.001
7. M. Feuerbacher, E. Wuertz, A. Kovacs, C. Thomas, Single-Crystal Growth of a FeCoCrMnAl High-Entropy Alloy. Mat. Res. Lett. 2 (2017) 128, doi:10.1080/21663831.2016.1234516
8. M. Feuerbacher, M. Heidelmann, and C. Thomas, Hexagonal High-Entropy Alloys. Mat. Res. Lett. 3 (2015) 1. doi:10.1080/21663831.2014.951493
9. P. Kozelj, S. Vrtnik, A. Jelen, S. Jazbec, Z. Jaglicic, S. Maiti, M. Feuerbacher, W. Steurer, and J. Dolinsek, Discovery of a Superconducting High-Entropy Alloy. Phys. Rev. Lett. 53 (2014) 187, doi.org/10.1103/PhysRevLett.113.107001