Regensburg 2025 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

O: Fachverband Oberflächenphysik

O 13: Organic Molecules on Inorganic Substrates: Adsorption and Growth

O 13.6: Vortrag

Montag, 17. März 2025, 16:15–16:30, H8

From Physical Trends to Structural Control: Insights into Phase Transition Times at Metal-Organic Interfaces — •Anna Werkovits, Simon B. Hollweger, and Oliver T. Hofmann — Institute of Solid State Physics, Graz University of Technology, Austria

At many metal-organic interfaces, molecules in the wetting layer undergo lying-standing transitions, significantly altering interface properties. Understanding the kinetics governing these transitions is essential for controlling structural evolution over time. This knowledge is particularly critical for tailoring interfaces based on either kinetically trapped or thermodynamically favoured structures.

To facilitate the design of interfaces, we develop a physically motivated surrogate model that estimates the phase transition times across a wide range of metal-organic interfaces. Using a systematic set of kinetic Monte Carlo simulations, incorporating variations in energetic landscapes and relative molecule sizes (representing hypothetical interface systems), we extract the physical relationships governing the timescales of phase transitions. These dependencies are analysed as functions of adsorption energies (lying and standing), kinetic barriers for reorientation and diffusion, molecule sizes, and environmental parameters such as temperature and pressure. This approach yields a formula that serves as a foundation for understanding trends, controlling structural evolution, and estimating timeframes for experiments and applications to ensure phase stability. Additionally, it enables the design of systems that remain stable over long periods, even in metastable states, advancing experimental and practical applications.

Keywords: phase transition; kinetic Monte Carlo; microkinetic simulations; metastabitily; metal-organic interfaces