CHE 598 Seminar
About the event
Professor Miquel Salmeron is a Senior Staff Scientist in the Materials Science Division of the Lawrence Berkeley National Laboratory and an Adjunct Professor in the Materials Science and Engineering Department at the University of California, Berkeley.
Dr. Salmeron received his B.A. in Physics from the University of Barcelona in Spain, an M.A. in Physics from the Universite Paul Sabatier in France, and a Ph.D. in Physics from the Universidad Autonoma de Madrid in Spain. His research focuses on fundamental studies of materials surfaces, including structure, chemical, electronic, and mechanical properties. His research topics include: a) single molecule adsorption, manipulation, reactions and diffusion, using Scanning Tunneling Microscopy (STM); b) nano-tribology using Atomic Force Microscopy and Surface Forces Apparatus; c) wetting and water-surface interactions using microscopy (STM), and spectroscopic techniques such as x-ray absorption spectroscopy, with the goal of understanding the molecular origin of wetting, solvation phenomena and the structure of solid-liquid interfaces; d) molecular electronics to understand how nanoparticles and molecules can be used to transport charge and heat with applications to solar cells. During his career he has developed many instruments and methodologies that make possible in situ studies of surfaces in gas and liquid environments, including: High Pressure Scanning Tunneling Microscopy, Ambient Pressure Photoelectron Spectroscopy, and X-ray Absorption Spectroscopy.
From Surfaces to Interfaces: Ambient Pressure XPS and Beyond
The rapidly increasing field of surfaces under ambient conditions of temperature, and pressure in gas and liquid environments, reflects the importance of understanding surface properties in conditions closer to practical situations. This has been enabled by the emergence in the last two decades of a number of new techniques, both spectroscopy and microscopy, that can deliver atomic scale information with the required surface/interface sensitivity. I will present a short review of recent advances to illustrate the novel understanding derived from the use of new techniques focusing on the gas–solid interface, where two barriers have been bridged: the pressure gap, and the temperature gap. The later gap is very important when dealing with weakly bound molecules, where only by the presence of gas at a suitable pressure can a measurable coverage of adsorbed molecules be achieved. The temperature gap manifests also in the removal of kinetic barriers. The formation of dense adsorbed layers at room temperature and above leads to drastic changes in their structure that affect their structure and chemical activity. Future developments to continue extending the range of pressures and to access solid-liquid interfaces will be mentioned.