Atomic Diffusion and Molecular Self-Assembly on Metal Surfaces.
Abstract: The research described herein focuses on understanding and
exploiting nanometer-scale surface phenomena with respect to surface reactivity and
self-assembled systems. Using scanning tunneling miscroscopy, atoms and small molecules
(i.e., fewer than 30 atoms) adsorbed on metal surfaces were
studied with the objective being to capture, understand, and manipulate the events
occurring a... read moret the interface between gases and solid surfaces. The specific approach was to
examine a variety of different but related chemical species in order to understand how
chemical functionality affects the assembly behavior of technologically important species
on metal surfaces. Using this systematic approach, in which, for example, only a single
atom (or group of atoms) in the adsorbed species was varied, it was possible to uncover
subtle differences in assembly behavior and overlayer stability. These differences are
explained in terms of the chemical properties of the differing atom(s), which are based on
well-established periodic trends and governed by electrostatics. Similar studies focusing
on varying ligand functionality are also presented. Findings from this research add to our
understanding of fundamental chemical interactions that govern assembly at the gas/solid
interface. Importantly, the work here contributes to the establishment of heuristic rules
that, in the future, could help predict assembly behavior. The impact of this research has
the potential to transform our approach to sensor technology, heterogeneous catalysis, and
other related fields.
Thesis (Ph.D.)--Tufts University, 2012.
Submitted to the Dept. of Chemistry.
Advisor: Charles Sykes.
Committee: Elena Rybak-Akimova, Albert Robbat, and Karsten Pohl.
Keywords: Chemistry, Physical chemistry, and Nanoscience.read less