Thesis: S.B., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2015. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 39-40). / The self-assembly of block copolymers (BCP) has been a promising area of research for nanolithography applications in microelectronics because of their ability to produce nano-scale level periodic structures with long-range order. Ideal BCPs for generating these nano-scale patterns fall within the strong segregation limit (SSL) and have a high interaction parameter to drive BCP phase transitions. BCP morphologies can vary from equilibrium structures such as spheres, cylinders, and gyroid, to metastable structures such as hexagonal perforated lamellar (HPL). A variety of processing techniques including solvent vapor annealing (SVA) have been developed in order to facilitate the phase transitions of BCPs from disordered to ordered states. SVA parameters which can affect the final film morphology include the swelling thickness of the film and solvent removal rate. Thermal modulation of the substrate was used to explore the effects of rapid solvent evaporation during the annealing process on the morphologies of the PS₁₆-b-PDMS₃₇ system. Additional cycles of solvent update and film reswelling were introduced into the annealing procedure to induce greater long-range ordering of film morphologies. Although a range of morphologies were explored, there was special focus on developing a procedure for mono-layer HPL structures for nanolithography applications. / by Annia Pan. / S.B.

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005. / Includes bibliographical references. / Thin films have a high surface-to-volume ratio and are therefore usually morphologically unstable. They tend to reduce their surface energy through transport of mass by diffusion. As a result, they decay into a collection of small isolated islands or particles. This solid-state process, known as thin film dewetting, can be initiated by grooving at grain boundaries or triple junctions. Dewetting of thin films on topographically modified substrates has many interesting characteristics. It is a novel self-assembly process for the formation of well-ordered nanoparticle arrays with narrow size distributions and uniform crystallographic orientation. Potential applications of particles resulting from templated thin film solid-state dewetting are reviewed. Applications in patterned magnetic information-storage media, plasmon waveguides, and catalytic growth of ordered arrays of semiconducting nanowires and carbon nanotubes are discussed. Templated dewetting technology has not been fully developed, and technological barriers are identified for all of the commercial applications considered. / (cont.) However, the self-assembly characteristics of templated dewetting may ultimately offer advantages in the manufacture of both patterned media and catalytic nanomaterial growth technologies. / by Emmanouil Frantzeskakis. / M.Eng.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995. / Includes bibliographical references (leaves 146-157). / by Attiganal Narayanaswamy Sreeram. / Sc.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1987. / Bibliography: leaves 162-164. / by John Victor Busch. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1986. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Vita. / Bibliography: leaves 141-146. / by Isabelle Goss. / M.S.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995. / Includes bibliographical references. / by Chong S. Yoon. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2009. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 134-139). / Without doubt, energy and environment are becoming central issues for the future. In this regard, not only device performance but also environmentally sustainable ways of making energy device is important. To meet these needs, a M13 virus based biological toolkit was utilized in this work for controlling nanostructures of lithium ion battery electrodes which is a critical process in developing electrodes materials for high power applications. The M13 biological toolkit provides specificity, versatility and multifunctionality for controlling nanostructure of the materials using basic biological principles. The versatile E4 virus template could nucleate active cathode materials at low temperature by an environmentally benign method. High power lithium ion battery cathode materials were fabricated using genetically programmed multifunctional virus as a versatile scaffold for the synthesis and assembly of materials. A novel strategy for specifically attaching electrochemically active materials to conducting carbon nanotubes networks through biological molecular recognition was developed by manipulating the two-genes of the M13 virus. Viral amorphous iron phosphates cathodes achieved remarkable and otherwise impossible high power performance using this multifunctional virus. This environmentally benign low temperature biological scaffold could facilitate new types of electrode materials by activating a class of materials that have been excluded because of their extremely low electronic conductivity. Architecting nanostructures was further extended to activate noble metal alloy nanowires as anodes for lithium ion batteries by alleviating mechanical stress. / (cont.) By demonstrating electrochemical activity of noble metal alloy nanowires with various compositions, the M13 biological toolkit extended its utility for the study on the basic electrochemical property of materials. / by Yun Jung Lee. / Ph.D.

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2009. / "May 2009." Cataloged from PDF version of thesis. / Includes bibliographical references (p. 49-50). / 'Black silicon' refers to silicon that has been treated in a laser-ablation process to incorporate large amounts of chalcogen dopants. The material has been found to have greatly increased absorbance of visible and infared wavelength light in comparison to undoped crystalline silicon. Selenium-doped black silicon that had been annealed at different temperatures were studied using transmission electron microscopy (TEM) and electron diffraction. The goal of the investigation was to characterize the structure of the laser-altered regions of the material. In addition, energy dispersive X-ray spectroscopy (EDX) was conducted in a scanning transmission electron microscope (STEM) in order to map spatial distribution of the selenium and the silicon were located within the material. The results of the TEM study showed roughly conical peaks of varying shapes protruding about 1 [mu]m from the surface of the material. The material is altered up to a depth of up to 1-2 [mu]m, where polycrystalline or amorphous layers were observed. Electron diffraction studies revealed increased crystallinity in the annealed sample. A continuous, sharp interface between the affected region and unaltered substrate was found and particles of diameter 5-100 nm embedded within the silicon were observed. The STEM-EDX studies showed that the selenium was dispersed inhomogenously throughout the material. The selenium is concentrated near the interface of the unaltered Si substrate and the laser-altered layer and a high local concentration of selenium in the embedded particles was recorded. The findings in this study provide a first look at the underlying structure of black silicon and will lead to future work characterizing the material. / by Arthur H. Reading. / S.B.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (p. 159-164). / To identify the most promising positive electrodes for Ca-based liquid metal batteries, the thermodynamic properties of diverse Ca-based liquid alloys were investigated. The thermodynamic properties of Ca-Sb alloys were determined by emf measurements. It was found that Sb as positive electrode would provide the highest voltage for Ca-based liquid metal batteries (1 V). The price of such a battery would be competitive for the grid-scale energy storage market. The impact of Pb, a natural impurity of Sb, was predicted successfully and confirmed via electrochemical measurements. It was shown that the impact on the open circuit voltage would be minor. Indeed, the interaction between Ca and Sb was demonstrated to be much stronger than between Ca and Pb using thermodynamic modeling, which explains why the partial thermodynamic properties of Ca would not vary much with the addition of Pb to Sb. However, the usage of the positive electrode would be reduced, which would limit the interest of a Pb-Sb positive electrode. Throughout this work, the molecular interaction volume model (MIVM) was used for the first time for alloys with thermodynamic properties showing strong negative deviation from ideality. This model showed that systems such as Ca-Sb have strong short-range order: Ca is most stable when its first nearest neighbors are Sb. This is consistent with what the more traditional thermodynamic model, the regular association model, would predict. The advantages of the MIVM are the absence of assumption regarding the composition of an associate, and the reduced number of fitting parameters (2 instead of 5). Based on the parameters derived from the thermodynamic modeling using the MIVM, a new potential of mixing for liquid alloys was defined to compare the strength of interaction in different Ca-based alloys. Comparing this trend with the strength of interaction in the solid state of these systems (assessed by the energy of formation of the intermetallics), the systems with the most stable intermetallics were found to have the strongest interaction in the liquid state. Eventually, a new criteria was formulated to select electrode materials for liquid metal batteries. Systems with the most stable intermetallics, which can be evaluated by the enthalpy of formation of these systems, will yield the highest voltage when assembled as positive and negative electrodes in a liquid metal battery. / by Sophie Poizeau. / Ph.D.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996. / Vita. / Includes bibliographical references (leaves 97-98). / by Lan H. Hoang. / M.S.