Structure and Reactivity of Solid Surfaces

The research activity of the group is focused on the determination of the geometric and electronic structure of solid surfaces, and on the characterization of their chemical reactivity. Clean and adsorbate covered transition metal surfaces, ultra-thin oxide films, surface alloys, self-assembled organic monolayers, and epitaxial graphene are investigated.

The experimental team is often involved in research projects at Elettra beamlines - in particular SuperEsca, Nanospectroscopy, and Aloisa - as well as at other international synchrotron radiation facilities.

The results are often corroborated with and compared to data from theoretical calculations performed by physicist both from the Department (Maria Peressi and Alfonso Baldereschi) and from other external institutions.

Our principal research theme consists in the investigation of the interaction of adsorbates with surfaces, in order to analyze the induced structural modifications, the formation of bonds, the changes in the electronic structure at the interface, and the elementary steps involved in surface processes (e.g. atomic and molecular diffusion, segregation, chemical reactions). We adopt investigation techniques exploiting diffraction, spectroscopy, and microscopy (Low Energy Electron Diffraction, X-ray Photoelectron Spectroscopy, Photoelectron Diffraction, Thermal Desorption Spectroscopy, low and variable temperature Scanning Tunneling Microscopy). Recently, a novel experimental setup has been designed and commissioned, dedicated to laser sum frequency generation vibrational spectroscopy (SFG). The latter technique can be exploited for the investigation of surfaces and interfaces both at high pressures and in liquid. It will first be employed for the study of (electro)-catalytic reduction mechanisms of carbon dioxide and its conversion into energy vectors and chemicals of applicative interest. These experimental approaches allow the investigation of surface processes also during their evolution. Atomic and molecular beams, also supersonic, are employed for the comprehension of gas-surface interaction mechanisms and for the study of surface reactivity in model systems. Furthermore, a thorough effort is dedicated to the constant and progressive update, development, and realization of the experimental setups of the group.

Selected recent findings are reported below.

See:

Variable and low temperature STM laboratory
IR-Vis Sum Frequency Generation vibronic spectroscopy laboratory
Surface Science Laboratory
ANCHOR Project

Head of Research Group
Head: 
Giovanni Comelli

Info

Last update: 10-23-2019 - 18:50