Most relevant scientific results

• Pioneered the use of atomically-resolved STM for directly observing point defects (single O vacancies) on TiO₂(110) [1], an approach that was followed by many groups world-wide. Ref. [1] was also one of the first papers that exemplified the prowess of combining STM and DFT for fundamental insights on oxide surfaces.
• Wrote a highly-cited review article [2] that established TiO₂ as the prototypical system in oxide surface science, and the relevance of surface-science based, fundamental insights to more applied fields.
• Showed how one can use the STM tip to manipulate subsurface O vacancies [3], opening the pathway to investigate, at the atomic scale, the potential-induced defect migration that is fundamental in solid state electrochemistry and in novel electronic devices such memristors.
• Used microscopy and spectroscopy to provide direct, real-space evidence for electron polarons [4]. Established that the polaronic behavior in the two TiO₂ polymorphs rutile and anatase is fundamentally different, and explained the role of polarons in the phase transition to a surface reconstruction on rutile TiO₂(110) [7] (together with Franchini and Kresse).
• Conducted surface science studies on well-defined perovskite surfaces. E.g., ref. [5] confirmed the theoretically-predicted, dynamic behavior of a single, dissociated water molecule on a perfect AO-terminated perovskite oxide.
• Adapted the use of UHV-based non-contact AFM for the detailed investigating surface chemistry on metal oxides. Ref. [6] shows how one can judiciously charge single, adsorbed O₂ molecules with the AFM/STM, and use local contact potential measurements to evaluate the shift of the electronic states with the presence of additional, charged molecules.
• Showed the direct influence of surface structure on O incorporation at an SOFC cathode model material [8]. This was done by adjusting the surface reconstruction of a prototypical perovskite (SrTiO₃(110)), and evaluating the ¹⁸O tracer behavior (together with Fleig and Franchini). This study culminated a series of investigations, where the structural evolution of SrTiO₃(110) was mapped out with great care, a prerequisite for the mechanistic understanding provided in [8].
• Provided detailed insights into surface polarity, a central concept in oxide surfaces and interfaces. Ref. [9] (together with Franchini) shows how an intrinsically polar oxide, KTaO₃(001), undergoes a series of compensation mechanisms when lifting kinetic barriers by raising the sample temperature.
• Devised a methodology of exposing samples to ultrapure water within a UHV environment. This avoiding any spurious contamination that is usually present in the ambient and enables atomically-resolved surface studies. Applying this method showed the likely cause of the light-based, amphiphilic behaviour of TiO₂ [10] .

Career

• 2010–present: Full Professor of Surface Science; Deputy Head Institute of Applied Physics
• 2006–2009: Yahoo! Founder Chair in Science and Engineering
• 2001–2009: Full Professor, Department of Physics, Tulane University, New Orleans, LA, USA
• 1999–2001: Associate Professor, Department of Physics, Tulane University, New Orleans, LA, USA
• 1993–1999: Tenure-track Assistant Professor, Department of Physics, Tulane University, New Orleans, LA, USA
• 1990–1993: Post-doctoral Research Associate, Department of Physics, Rutgers University, New Jersey, U.S.A. (Advisor: T.E. Madey)

Education

• 1998: Habilitation in Experimental Physics, TU Wien, Austria
• 1990: Ph.D. in Engineering Physics (Dr. techn.), TU Wien, Austria
• 1986: M.Sc. in Engineering Physics (Dipl.-Ing.), TU Wien, Austria