Download or read book Exploratory Synthesis in the Quaternary System Including Rare earth Transition Metal Gallium and a Tetrelide Using Liquid Gallium as a Solvent written by Marina A. Zhuravleva and published by . This book was released on 2002 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2003 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Doctoral Dissertations written by and published by . This book was released on 2002 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Characterization of Rare Earth nickel gallium Ternary Intermetallics written by Kandace Renee Thomas and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Interfacial Chemistry of Liquid Metals Eutectic Gallium Indium E GaIn written by Logan Ali Stewart and published by . This book was released on 2019 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium-based liquid metal alloys have garnered attention for their use in self-healing and flexible electronics, soft robotics, catalysis, and biomedicine. Advances in these next-generation materials have only been made possible through understanding the liquid-metal interfaces and the interactions of matter with these liquids. We propose that liquid metal chemistry of gallium and gallium-based alloys can be subdivided into a series of interfacial phenomenon. To study the interfacial properties of liquid metal, eutectic gallium indium (E-GaIn), a non-toxic liquid metal alloy comprised of ~75% gallium and ~25% indium, and has a melting temperature of 15.5 C, was employed for its liquid state at room temperature. With an overview of the breadth of chemistry involved within liquid metal systems, we first consider the oxidation of liquid metals in air. Room-temperature liquid metals, their interactions in air, and the kinetics of oxidation are critical first steps towards understanding the materials properties of liquid metals, such as surface-energy/surface-tension that originate at the metal-oxide interface. Once understood, this oxidation can be prevented via surface-bound ligands. We employed gallium-thiol chemistry and bi-functional thiol molecules as capping ligands for the surface stabilization of gallium-based liquid-metal nanostructures. These surface stabilization effects, within mixtures of liquid metal and polar solution, such as water and ethanol, are examined as a new type of emulsified system. These emulsified systems, with the help of surface-active molecules, can exist in both their singly and doubly emulsified forms. Like mercury and other liquid metals, E-GaIn has a high surface tension, which when broken can form ultra-small droplets, ~4 nm. These ultra-small liquid metal droplets were found to undergo higher order assemblies in the form of fractal aggregates under evaporation of the surrounding solvent. When examining the doubly emulsified form, these liquid metal droplets present a novel approach for the encapsulation of cargo. The material properties of E-GaIn present an interesting avenue for the study of nanocarriers. Eutectic gallium indium, which has low toxicity, enable considering this liquid metal for drug-delivery applications. Furthermore, where traditional nanoparticle carriers typically have cargo decorated on the surface, or within pores and imperfections; liquid-metal double emulsions, which have a non-metallic phase embedded within the core of the liquid metal droplets, allow for cargo loading much larger than the surface of the nanostructure. Lastly, competition for interfaces and the role of self-assembly at metallic interfaces presents a scaffold for the post-encapsulation functionalization of liquid metal carriers. The 'skin' of liquid E-GaIn, whether comprised of metal oxide, metal thiolate, or pristine surface can act as a barrier for reaction kinetics, such as in the case of surface oxidation and the prevention of it with thiol/thiolate assemblies at the liquid metal interface, or a regenerative reactive interface, as in the case of surface-initiated galvanic reduction. Galvanic reduction with gallium, as the name implies, can act as a free-electron surface for the reduction of simple metal salts. Similar to hanging mercury drop experiments, liquid metals provide a pristine, self-regenerating, liquid metal surface. We explore the galvanic reduction of silver salts on nanoscopic liquid metal seeds via solution-liquid-solid-growth of silver nanovines. We found these arboriform liquid metal structures were grown as diffusion-limited aggregates and we were able to impart control on both the growth front thickness and aspect ratio. The manipulation of liquid metals with surface-active molecules will have applications in next-generation devices and soft robotics. By incorporating liquid metal as the conductive contacts, we enable malleable devices. Liquid metals enable new applications of traditional conductive materials with certain advantages. We envision robots, sensors, and a variety of future prospects where liquid metal can open new doors to a variety of applications. In an effort to explore these devices, we have shown that E GaIn is an ideal contact material for an ultra-thin indium oxide based field-effect transistor (FET). These liquid-metal-enabled devices provide lower barriers to charge transfer, yielding lower power devices as compared to gold. Liquid-metal-enabled emulsions, materials, and devices present new chapters in inorganic chemistry, materials chemistry, engineering, nanoscience, and medicine. By looking at the interfacial phenomenon that dictates the interactions of liquid metal with the environment, we explore these avenues of control and application. With the rise in availability for three-dimensional (3-D) printers, liquid metal and hybrid materials comprised of liquid-metal-based emulsions are a new frontier. The field of liquid-metal-enabled materials remains relatively unexplored.
Download or read book Rare Earth Doped Gallium Nitride Powders written by Tiju Thomas and published by . This book was released on 2011 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gallium Nitride is a III-V compound semiconductor that has attracted a lot of interest among both applied and basic researchers because of its potential applications in optoelectronic, high power and high frequency devices. However, many questions about the material remain unanswered. In this thesis, we will present our investigation of GaN. We will first describe an ammonothermal method for the synthesis of undoped and rare earth doped GaN powders. Using careful observations and calculations, we show that the powder growth is primarily a liquid phase phenomenon. We also present a chemical method to achieve luminescence enhancement in ammonothermally grown Eu:GaN powders. Based on arguments drawn from the surface chemistry and XRD of these samples, we conclude that elimination of dark mixed oxides from the powder results in the observed luminescence enhancement. We also demonstrate a nano Eu:GaN synthesis process using a simple mechanical topdown method. The optical properties of nano Eu:GaN prepared in this manner is comparable to that of the bulk material. Based on a similar mechanical process we synthesized nano Er:GaN powders that emit in the C band (1.55 m). The mechanism involved in the luminescence of rare earth doped GaN is investigated using thermal quenching and high pressure studies. Our results suggest that an exciton bound to rare earth structured isovalent impurity (RESI) is responsible for luminescence in these materials. Luminescence quenching and pressure dependent photoluminescence enhancement in RE:GaN can be explained based on this model. Our results clearly suggest that thermal quenching can be undone by application of pressure. These powders are discovered to be fairly radiation hard as well. In the last section of this thesis, we will present an electrophoretic technique to deposit nano GaN on a fluorine doped tin oxide coated glass substrate. The technique can be easily adapted to grow layered structures that can find application in optical fibers and as a laser gain medium. Preliminary results for highly densified GaN ceramic obtained using a hot-press process are discussed. These results suggest that further densification is necessary for achieving a completely transparent GaN ceramic made out of ammonothermally synthesized GaN powders.
Download or read book Beginner s Guide to Flux Crystal Growth written by Makoto Tachibana and published by Springer. This book was released on 2017-10-26 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the principles and techniques of crystal growth by the flux method, which is arguably the most useful way to obtain millimeter- to centimeter-sized single crystals for physical research. As it is possible to find an appropriate solvent (“flux”) for nearly all inorganic materials, the flux method can be applied to the growth of many crystals ranging from transition metal oxides to intermetallic compounds. Both important principles and experimental procedures are described in a clear and accessible manner. Practical advice on various aspects of the experiment, which is not readily available in the literature, will assist the beginning graduate students in setting up the lab and conducting successful crystal growth. The mechanisms of crystal growth at an elementary level are also provided to better understand the techniques and to help in assessing the quality of the crystals. The book also contains many photographs of beautiful crystals with important physical properties of current interest, such as high-temperature superconductors, strongly correlated electronic systems, topological insulators, relaxor ferroelectrics, low-dimensional quantum magnets, non-linear optical materials, and multiferroics.
Download or read book The Electric Furnace written by Henri Moissan and published by . This book was released on 1904 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
