The physical and chemical properties of the surfaces of materials play an important role in many large scale applications, such as in heterogeneous catalysis and corrosion inhibition. With the shrinking dimensions of electronic and optoelectronic devices, surface properties are of increasing relevance in many fields of modern technology, such as in thin film growth. In the emerging field which combines electronic devices with biological applications the surface properties dominate issues such as biocompatibility. The last two decades have seen a rapid progress in our understanding of fundamental processes on highly idealized surfaces.
The importance of turning towards a fundamental understanding of the properties of highly complex surfaces is highlighted, among other things, by an ever-increasing appreciation of the experimental methods and results of basic research in surface analysis by industrial scientists and engineers. Many of these techniques, such as atomic force microscopy, X-ray photoemission, and optical methods are nowadays routinely used in the industrial environment. This overlap of interest in surface processes is reflected in the high demand for well-trained scientific personnel with an excellent command of the concepts and techniques of modern surface science. This demand, which is hardly met by the current number of graduates in the field, is expected to increase in coming years.
The International Max Planck Research School on “Functional Interfaces in Physics and Chemistry” aims at combining the expertise of several strong research groups in the Humboldt Universität zu Berlin, the Freie Universität Berlin, the Technische Universität Berlin, the Universität Potsdam, and the Fritz-Haber-Institut der Max-Planck-Gesellschaft creating a unique opportunity for foreign and German students in terms of cutting-edge research and a thorough training in the methods, concepts, and theoretical basis of the physics and chemistry of surfaces. The Research School provides an interdisciplinary environment, and a wealth of methods using state-of-the-art equipment.
Our plan of research encompasses a wide range of complex surfaces and interfaces. Surface science has evolved, over the last two decades, from a predominance of studies on highly idealized, single-phase, single-crystalline materials, to address complex multi-phase systems such as nanoparticles, multiply layered systems, and combinations between different material classes such as metal-oxide structures. An excellent example of research in this field relates to chemical processes on surfaces. On oxide surfaces, elementary processes in heterogeneous catalysis are studied, while an understanding of reactions on semiconductors is important for a wide range of applications. Surfaces of other materials which so far have not been widely studied in surface science because of their complexity, such as nitrides and carbides, are also important from a technological point of view and will be investigated. Finally, magnetic films and multilayers are exciting topics in view of their emerging use in magnetic data storage.
The investigation of such complex surfaces is a demanding task and calls for the collaboration between groups from various disciplines, focusing all experimental tools on the study of a small range of systems. This provides students with exciting possibilities for working together on a common theme using a variety of approaches. Many of the above-mentioned compound surfaces are characterized by complex surface morphologies, and a tendency to support the formation of defect structures, on which interest has focused only recently. These defects often give rise to considerable restructuring of the surface, for example as a function of temperature, which in turn affects its chemical reactivity. This has influence on nucleation and growth of metal aggregates, a field that is just emerging in surface research. Oxide surfaces, modified by metal adsorption, exhibit a strongly different chemical reactivity compared to their clean surface counterparts. In specific combinations, metal-modified compound surfaces may be considered as models for heterogeneous catalysts. It is one of the scientific goals of this Research School to tailor the surface structure of such systems with a view to inferring structure-reactivity relations which are otherwise difficult to obtain.
Such investigations have implications that obviously go far beyond reactivity studies. Oxides exhibit transport properties which range from insulators to superconductors, and their surfaces and interfaces may play an important role in this respect, too. Moreover, oxides are important as insulating gate oxides in microelectronic devices, which have reached thicknesses down to about 5 nm in modern devices such as Intel’s Pentium IV microprocessors; it is thus interesting to study the structures of oxide layers on specific substrates and to elucidate their properties in the limit of one to several atomic layers. The modern Materials Science literature provides a wealth of examples demonstrating the importance of understanding surfaces and interfaces of complex materials on an atomic level.
Our aim is to address such surface- and interface-related problems from an experimental as well as theoretical point of view. The expertise available at the two Universities and the Fritz-Haber-Institut is an excellent basis for research and training in this respect, as evident from the list of groups involved in the Research School; it involves groups which have a strong collaborative effort. In view of the close collaboration among the groups, it is intended to have students work with the various techniques and approaches offered by groups from both sides, spending part of their time in university- or Fritz-Haber-groups as appropriate for their field of study. Berlin, with its metropolitan flair and open, multi-cultural atmosphere provides an attractive environment for the participation of foreign students in the Research School.