Design, Synthesis, and Characterization of Metal Oxide Nanostructures Formed Through Natural and Direct-Write Processes
Datum
2019-09-18
Autor:innen
Zeitschriftentitel
ISSN der Zeitschrift
Bandtitel
Verlag
University of Oregon
Zusammenfassung
Inorganic metal oxide nanomaterials are of interest because they exhibit unique properties that can aid in applications including catalysis, energy storage, sensing, and medicine. These properties arise from nanoscale structure, but understanding what structural aspects determine properties and subsequently controlling them remains difficult. Electron microscopes have been integral in both the fabrication of nanomaterials and the analysis of nanoscale structure, enabling the examination of structure related properties and the design of new materials. Direct-writing of metal oxide nanomaterials through electron beam lithography offers a method to explore structural control. Direct-write processes begin from precursors that must first undergo a chemical transformation in a bottom-up approach. However, the chemistry that occurs during electron irradiation is not well understood. The work described in this dissertation investigates the formation process of nanoscale metal oxides through both direct-write electron beam processes and processes used by nature, relying upon electron microscopy to both fabricate and analyze the materials.
This dissertation first introduces recent improvements in characterization techniques that not only advance our understanding of materials for the future, but also allow investigation of man-made materials throughout history. Only recently have improvements in characterization techniques allowed us to uncover the historical use of nanomaterials in cultural heritage, providing an unconventional link between our past, present, and future. The first four studies presented here investigate the chemistry of direct-write electron beam processes. These studies consider the chemistry of the electron beam as a reagent, the importance of precursor structure in the patterning process, the chemical transformations that occur during direct-writing, and the potential to control local structure through precursor choice. These studies all utilize the electron beam as a fabrication tool, identifying ways in which direct-writing can improve device processing and design of materials. The fifth study uses the electron beam as an analysis tool on an unusual cultural heritage sample: a nanoscale metal oxide naturally forming on architectural stone. Analyzing the nanoscale structure of the oxide better informs its natural formation chemistry, which also has implications for a variety of other fields.
This dissertation includes previously published and unpublished co-authored material.
Beschreibung
Schlagwörter
Electron Microscopy, Inorganic Clusters, Lithography, Metal Oxides, Nanomaterials