A novel cryogenic variable temperature UHV STM has been constructed and utilized to investigate the dynamical behavior of isolated organic molecules covalently bound to silicon surfaces.
The microscope can be operated from 8-300 K, and exhibits extremely low drift rates. A new design has been implemented for the rails (used...
This dissertation demonstrates how self-assembly can direct nanoscale ordering and optimize electronic properties of organic semiconductors, as well as organic-inorganic hybrids. In excitonic solar cells, controlling the ordering and interfaces between electron-transporting (n-type) and hole-transporting (p-type) domains is crucial. In addressing this challenge, hybrid nanostructures were designed by mineralization of...
The work presented in this dissertation focuses on ceramic anode materials for solid oxide fuel cells (SOFCs). The primary goal was to characterize the anode and relate the electrochemical behavior to the microstructure. The anode that was most extensively studied in this work was a composite of Gd0.10Ce0.90O1.95 (GDC) and...
Aluminum alloys strengthened with coherent (L1<sub>2</sub>), nanosize Al<sub>3</sub>Sc precipitates may be used as structural materials at elevated temperatures. They are creep resistant at 300°C and exhibit a threshold stress, below which creep is not measurable. Introducing ternary alloying additions, such as rare-earth elements (RE=Y, Dy, Er), that segregate within Al<sub>3</sub>Sc...
A series of investigations was undertaken to explore the processing and properties of porous titanium with 6 wt% Al and 4 wt% vanadium (Ti-6Al-4V) and an equiatomic nickel-titanium alloy (NiTi). In this study, porous materials were created in the solid state by entrapping argon in a powder compact, and subsequently...
Oxide surface structures play a key role in many technological processes, including catalysis, thin film growth, and layered structures, and a thorough understanding of surface structures and surface structure dynamics is required in order to better engineer materials systems for these processes. This research works towards understanding these fundamental principles...
Over the past two decades photonic crystals (PhCs) have emerged as a promising new class of materials which offers unprecedented control of light in materials. Recently, atomic layer deposition (ALD) has been shown to be a powerful tool for the infiltration of 3D templates with dielectric or semiconducting materials, which...
Polymers and polyelectrolytes are ideal tools for the development of novel self-assembled materials. The ability to control the length-scales of self-assembly, and thus the properties, for soft materials lies in the understanding and subsequent manipulation of competing intermolecular interactions, such as hydrophobicity, hydrogen bonding, van der Waals, electrostatics. In this...
The optical and magneto-optical properties of the ferromagnetic semiconductors, InMnAs and its alloy InMnAsP were investigated to determine the band structure and nature of the ferromagnetism in these materials. Alloys were grown by metal-organic vapor phase epitaxy. Infrared absorption of InMnAs was investigated to determine the presence and properties of...
Biomorphic silicon carbide (bioSiC) is a novel porous ceramic material derived directly from wood precursors. This material is fabricated by pyrolysis of a natural wood precursor in an inert atmosphere leaving an amorphous carbon scaffold. The amorphous carbon is infiltrated with molten Si in vacuum at elevated temperature, which reacts...