Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2013. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 45-47). / One of the key objectives in the realm of flexible electronics and flexible power sources is to achieve large-area, low-cost, scalable production of flexible systems. In this thesis we propose a new Li-ion battery architecture in a fiber form that could be the building block to large-area, conformal, flexible power sources, achieved through fiber thermal drawing. This architecture is based on the key-finding of using thermally induced phase separation as a method to introduce porous structures inside thermally drawn fibers for the very first time. This new versatile process allows us to incorporate ionically conductive gel-polymer electrolytes in fiber cores in a very simple way, with ionic conductivities suitable for a battery application. The rest of our proposed infiber battery architecture is composed of composite electrodes, which we fabricate and characterize. A model system is tested and a detailed pathway towards the first successful fabrication of a Li-ion fiber battery is given. / by Benjamin Grena. / S.M.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2016. / Cataloged from PDF version of thesis. / Includes bibliographical references (pages 143-160). / Understanding and mastering the kinetics of oxygen electrocatalysis is instrumental to enabling solar fuels, fuel cells, electrolyzers, and metal-air batteries. Non-precious transition metal oxides show promise as cost-effective materials in such devices. Leveraging the wealth of solid-state physics understanding developed for this class of materials in the past few decades, new theories and strategies can be explored for designing optimal catalysts. This work presents a framework for the rational design of transition-metal perovskite oxide catalysts that can accelerate the development of highly active catalysts for more efficient energy storage and conversion systems. We describe a method for the synthesis of X-ray emission, absorption, and photoelectron spectroscopy data to experimentally determine the electronic structure of oxides on an absolute energy scale, as well as extract key electronic parameters associated with the material. Using this approach, we show that the charge-transfer energy - a parameter that captures the energy configuration of oxygen and transition-metal valence electrons - is a central descriptor capable of modifying both the oxygen evolution kinetics and mechanism. Its role in determining the absolute band energies of a catalyst can rationalize the differences in the electron-transfer and proton-transfer kinetics across oxide chemistries. Furthermore, we corroborate that the charge-transfer energy is one of the most influential parameters on the oxygen evolution reaction through a statistical analysis of a multitude of structure-activity relationships. The quantitative models generated by this analysis can then be used to rapidly screen oxide materials across a wide chemical space for highthroughput materials discovery. / by Wesley T. Hong. / Ph. D.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1991. / Vita. / Includes bibliographical references. / by Navtej Singh Saluja. / Sc.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2005. / Includes bibliographical references (p. 52-55). / Local drug delivery is a fast expanding field, and has been a center of attention for researchers in medicine in the last decade. Its advantages over systemic drug delivery are clear in cancer therapy, with localized tumors. A silicon microelectromechanical drug delivery device was fabricated for the purpose of delivering chemotherapeutic agents such-as carmustine, a potent brain cancer drug, directly to the site of the tumor. Limitations in the delivery capacity of the device led to the design of a new package. This package is made from thermally bonded Pyrex® 7740 frames that are anodically bonded to the drug delivery chip. It increases the capacity of the chip, is smaller than the previous package and possesses true hermeticity, because of the bonding processes involved. This work describes the fabrication steps of the new package and a problem with the thermal bonding of Pyrex® frames preventing the achievement of a package true to the original design. A temporary solution was devised and the completed package was tested with regards to its intended goals. It managed to increase the load capacity of the chip by a, factor of 10, with potential for more, while decreasing the overall size of the package. Short-term hermeticity was achieved for this package by using a UV-cured epoxy to bond some pieces, which was not in the original design. Future work will focus on finding a permanent solution to the aforementioned problem, and directions for it were suggested. / by Hong Linh Ho Duc. / S.M.

Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995. / Includes bibliographical references (leaves 204). / by Michael James Liberatore. / Sc.D.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2008. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / In title on t.p., double underscored "x" appears as subscript. / Includes bibliographical references (p. 68-71). / The past two decades have seen advancements in high temperature superconducting cables for use in applications such as electrical transmission lines, propulsion systems, and mobile power generation systems. This work describes the development of a non-fluorine precursor solution for YBCO films with high critical current densities (Jc). An aqueous nitrate precursor solution system was selected from three possible precursor solution systems. It was further developed to produce YBCO films with Jc > 1 MA/cm2. Films up to ~800 nm thickness were made, and Jc > 1 MA/cm2 was obtained for films of over ~400 nm thickness. The developed aqueous solution contained a rheology modifier (hydroxyethyl cellulose / HEC), nitrates of Y, Ba, and Cu, and chelating agents (polyethylene glycol / PEG and sucrose). The total organic content was ~12 wt% of the entire solution, and the total cation concentration was ~0.7 M. The rheology modifying polymer determined the thickness of the deposited films. This allowed for the deposition of films with higher thickness than would be dictated by the total dissolved cations alone. A low temperature decomposition process was developed based on analyses of the chemical reactions that take place in the precursor films as they were heated. This process produced smooth and defect-free intermediate films that were stable under ambient conditions. These films were then heat treated to convert them into YBCO films. Recommendations for future work include further improvements to the precursor solution, including more effective chelating agents and possible alternative solvent systems. Intermediate films thicker than 2.5 [mu]m still tended to have surface defects. / (cont.) Additional in-depth thermal analysis would further show how these defects develop, and adjustments to the decomposition process could be made accordingly. High resolution plan-view and cross-sectional microstructures of the films between the precursor state and their converted forms is recommended. These future studies will be valuable in further improving the performance and thickness of films derived from the non-fluorine precursor solution developed in this thesis. / Yoda Rante Patta. / S.M.

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2015. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references. / Complex oxide thin films offer unique functionalities which can potentially extend the utility of current storage, processing and optical isolator technologies. In this thesis, we present three categories of studies on complex oxide growth using pulsed laser deposition (PLD) and structural, magnetic, magneto-optical and ferroelectric characterization. We first focused on enhancing integrated magneto-optical isolator performance by improving the growth method of magneto-optical Ce1Y2Fe5O12 (Ce:YIG) films. The spectral and substrate orientation dependence of the magneto-optical figure of merit of epitaxial Ce: YIG on GGG substrates show very high magneto-optical figure of merit (379-400° dB-1 at [lambda] = 1550 nm for all substrate orientations). The thermal budgets of Ce: YIG growth on ShN4 (2 high temperature PLD steps and a rapid thermal anneal, RTA), silicon-on-insulator substrates (a high and a low temperature PLD step and a RTA) and optical resonator chips (one PLD step, one RTA, YIG seed layer from the top) were progressively reduced to achieve improved integrated optical isolators with low insertion loss of 7.4 ± 1.8 dB and an isolation ratio of 13.0 ± 2.2 dB. We demonstrated that the ferrimagnetic insulator YIG thin films (Y3Fe5O12) epitaxially grown on GGG substrates achieve ultralow Gilbert damping of spin waves ([alpha] = 2.2-7 x 10-4 ), which enable em-long in-plane propagation of spin waves. This demonstration enables researchers to fabricate near-dissipationless magnon-based logic computers. Finally, we present a substitutionally-doped perovksite, STCo30 (Sr Ti0.70 CO0.30 O3-[delta]) integrated on Si, STO (100), and on Nb:STO substrates. This perovskite oxide has been found to exhibit ferroelectricity and magnetism at room temperature. Experimental results on magnetism, ferroelectricity and structure were reproduced using density functional theory simulations. / by Mehmet Cengiz Onbaş̧lı. / Ph. D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1995. / Includes bibliographical references (p. 591-619). / by Marlene Ann Spears. / Ph.D.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990. / Includes bibliographic references (leaves 174-179). / by Pinyen Lin. / Ph.D.

Thesis: S.M., Massachusetts Institute of Technology, Department of Materials Science and Engineering, 2017. / This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. / Cataloged from student-submitted PDF version of thesis. / Includes bibliographical references (pages 95-99). / The design and validation of new alloys for engineering applications is limited by the speed at which materials may be tested. In particular, there exist few methods by which the thermal, mechanical, and structural properties of materials may be monitored in conditions that are dynamically changing their microstructure. These conditions, such as heat treatments, radiation exposure, or corrosive environments, are common when material performance needs to be validated. To offset this lack of capability, new non-destructive experimental tools must be developed to facilitate on-line, realtime testing of materials undergoing some type of evolution. In this thesis, a flexible, all-optical methodology known as dual heterodyne phase collection transient grating spectroscopy is developed for this purpose. This method adapts a traditional spectroscopic technique sensitive to thermal and mechanical properties for real-time use. A formalism is also developed to quantify both elastic and thermal transport properties of materials with second-scale resolution. These new tools are then used to study the short-timescale oxidation kinetics of Fe-12Cr-2Si, a model alloy with oxide layer formation properties similar to large classes of Fr-Cr alloys. By monitoring the effect of thin oxide layers on surface thermal transport, there exists a pathway to continuously determine the thickness of a tens of nanometers thick growing oxide layer in real-time. Despite the lack of clarity in the particular set of experimental results presented here, the potential for the methods developed in this thesis is large. In-situ materials testing of this type may allow for a drastic increase in the pace of materials development by reducing the need for post-evolution, destructive materials testing between each design iteration. / by Cody Andrew Dennett. / S.M.