Beam deflection and photoabsorption studies of metal, water, and 'superatom' nanoclusters

University Of Southern California, Los Angeles CA

Investigators

Abstract

Studies of beams of nanoclusters (small-sized aggregates made up of several to several thousand atoms or molecules) utilize atomic and molecular beam concepts and methods to gain insight into the microscopic mechanisms of nano-scale as well as bulk-scale and surface phenomena. This project will utilize laser-induced fragmentation and electric field-induced deviation of metal and water cluster systems possessing strong permanent or induced electric dipole moments. The main goal is to investigate the electric susceptibility of water, metal, and "superatom" clusters as a function of their internal temperature. "Superatoms" are particularly stable and symmetric clusters which have been proposed to possess closed electronic and geometrical shells. The results will reveal such effects as the melting transition of a nanoscale icicle, charge transfer between gold and silver clusters and surface impurities, the formation of "superatomic molecules," and the interplay between electronic and structural motifs as the particle size increases atom-by-atom. The experiments will provide stringent tests and benchmarks for a number of current theoretical models. On the technical side, the broader impact of the project lies in its relevance for understanding nanomaterial building blocks and for optimization of molecular sensors and nanocatalysts. On the human side, the program will offer graduate students thorough training in an inherently interdisciplinary field, promote undergraduate involvement in research, and contribute to interdepartmental recruitment and outreach activities.