Ulrike Diebold
Vice President, Austrian Academy of Sciences (since 2022)
Professor for Surface Science, TU Wien
“Surface Science – from Atomically-Resolved Surface Structure to Thin Film Growth”
Monday, April 26, 2027, 8:00 a.m.
Surfaces play an important role in thin film growth and the functionality of coatings. The atomic structure and mesoscale morphology of the substrate affect the growth process in epitaxial deposition techniques, and the chemical and physical behavior of materials are often governed by their surface properties.
In the talk, I will highlight recent progress in atomically-resolved surface science techniques relevant to these issues. Non-contact AFM in ultrahigh vacuum is now capable of providing atomically-resolved images of very insulating materials such as Al2O3, a preferred substrate for the epitaxial growth of electronic materials. When given enough thermal energy, the Al2O3 (0001) forms a complex reconstruction; the low-temperature bulk-terminated phase is inhomogeneous and rough.
Reconstructions are prevalent in multi-element materials, and different surface phases evolve as a function of chemical potential. These influence surface diffusion, flatness, and surface chemistry, and how they evolve during growth can be used as a highly sensitive measure to evaluate non-stoichiometric deposition of complex oxides.