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Surface & interface phonons
Vibrational states at free surfaces, buried interfaces, and atomically thin films, including localized and hybridized modes.
Nanoscale phonons · surfaces · interfaces
Surface and Interface Dynamics of Nanoscale Materials
We study how atomic vibrations at surfaces and interfaces impact the properties of thin films and nanostructures. Our work combines epitaxial growth, in situ synchrotron radiation scattering and spectroscopy, and first-principles calculations to reveal how size, strain, bonding, and reduced dimensionality reshape the phonon spectra of functional nanomaterials.
Research programme
Atomic motion as a design parameter
The central question is how reduced dimensionality, surfaces, interfaces, and bonding modify atomic motion — and how these changes can be used to control materials properties.
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Phonon confinement
Dimensional crossover from bulk crystals to ultrathin films, nanoislands, and nanowires.
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Coupled dynamics
Interactions between lattice vibrations, charge, spin, magnetism, entropy, and functional response.
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Phonon engineering
Designing vibrational spectra for thermal management, energy materials, nanoelectronics, and quantum technologies.
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Surfaces and interfaces are dynamic materials per se
They possess modified force constants, localized vibrational states, and energy-transfer pathways that can govern the macroscopic behavior of nanoscale systems.
Intrinsic vibrational states of surfaces and interfaces
How do bonding, strain, roughness, intermixing, and symmetry breaking create non-bulk phonon spectra?
Nanoscale energy flow
Which phonons carry heat along and across surfaces and interfaces, and how can their propagation be controlled?
Function from atomic motion
How do phonons govern electronic, magnetic, elastic, and thermodynamic properties of nanoscale materials?
From spectroscopy to design
How can element-specific phonon spectroscopy and modelling guide phonon-engineered nanomaterials?
Methods
Controlled synthesis, spectroscopy, and modelling
Our approach combines atomically controlled samples preparation with element-specific phonon spectroscopy and quantitative lattice dynamics calculations.
Growth
- Controlled conditions (UHV)
- Molecular beam epitaxy
- Ultrathin films and nanostructures
Characterization
- RHEED / LEED
- Auger / XPS
- AFM / SEM
- MOKE
Advanced synchrotron radiation methods
- Nuclear resonant scattering
- X-ray absorption spectroscopy
- Inelastic X-ray scattering
Theory and modelling (collaboration)
- DFT calculations
- Lattice dynamics
- Thermodynamic & elastic properties
Selected publications
Publication highlights
Anomalous atomic dynamics in self-organized rare earth silicide nanoislands and nanowires unveiled
Original publication:
Phonons in Epitaxial DySi2: From the Bulk to Self-Organized Nanoislands and Nanowires Phys. Rev. Lett. 135, 256202 (2025) Full publication list →
2024
Phonons and thermodynamics of thin film solar cells
Kesterite thin-film solar cells
2022
Surface & interface dynamics
Ultrathin high-k rare earth oxide films
2020
Phonons in functional nanostructures
Iron silicide nanostructures for future nanoelectronics
People
Team and alumni
We train next generation scientists for industrial research and academia.
Group leaderDr. Svetoslav Stankov — surface science and synchrotron radiation
Current membersSagar Bisoyi - PhD student. Thesis title: Growth, structure and lattice dynamics of core-shell nanowires.
Alumni1 Postdoc, 4 PhDs, 3 Masters, 2 Bachelors, 3 Interships.
Teaching
Teaching and supervision
Co-lecturer for the following courses in the Master's program of the Faculty of Physics, KIT.
X-ray Physics I: Scattering, Diffraction and Spectroscopy on Crystals, Thin Films and NanostructuresLecture with tutorials and a practicum.
Accelerators and Synchrotron Radiation for Materials Research with Tutorials and a Practical TrainingTwo-weeks block lecture with tutorials and a practicum.
News and open positions
Recent activity
Lattice dynamics of thin films and nanostructures from nuclear inelastic scattering supported by ab initio theory
ESRF User Meeting 2026, Tutorial on Lattice dynamics and nuclear inelastic scattering.
Lattice dynamics of thin films and nanostructures from nuclear inelastic scattering and ab initio theory
Full list of talks →Ab initio study of the anharmonic properties and thermal conductivity in β-FeSi2, Comput. Condens. Matter 47, e01322 (2026)
First-principles calculations are used to study lattice dynamics, Raman spectra, phonon lifetimes, frequency shifts, and phonon-mediated heat transport in semiconductor β-FeSi₂.
Full publication list →We offer Bachelor and Master theses in the field of surface science and modern synchrotron radiation methods. A currently offered topic:
Please contact me directly for more details.
Contact →Funding
Financial support
The group is financially supported by the Initiative and Networking Funds of the President of the Helmholtz Association and the Karlsruhe Institute of Technology (contract VH-NG-625) and by the Federal Ministry of Research, Technology and Space BMFTR via the Verbundprojekt NUKFER (contract 05K16VK4) and the Verbundprojekt LANRS (contract 05K22VK2).
Contact
Get in touch
Please contact me directly for reprints or other queries.