CAREER: Synthesis of New Materials in Mixed Molten Metal Solvents

Florida State University, Tallahassee FL

Investigators

Abstract

TECHNICAL EXPLANATION The goal of this project is to synthesize new materials in mixed molten metal solvents. It focuses on two classes of materials, intermetallics and suboxides. Synthesis in molten metals allows for low reaction temperatures, which can result in the formation of unusual new metastable phases. The proposed research will investigate the effects of combining two different metals to act as a mixed solvent for the synthesis of intermetallics and suboxides. New intermetallic phases will be synthesized by combining elemental reactants in low melting metal mixtures such as a calcium-zink eutectic or a cerium-nickel eutectic. The products will be structurally characterized using X-ray crystallography, and they will be tested for potential hydrogen storage applications and magnetic ordering. In the exploration of suboxide compound synthesis from oxide precursors, the molten metal flux will act not only as a solvent, but also as a reducing agent toward the oxide reactants. Flux mixtures of a strongly reducing metal (such as sodium, magnesium, calcium, aluminum, or lanthanum) and a more inert metal (such as tin, indium, gallium, or bismuth) will be prepared in varying ratios to control the extent of reduction of a given oxide reactant. By controlling the electrochemical power of the flux mixture, it may be possible to tailor a subvalent product with a desired ratio of ionic and conducting structural moieties, and thereby design specific electronic properties such as band gap and work function. The resulting materials will be characterized using X-ray crystallography, solid state Nuclear Magnetic Resonance, and optical measurements. NON-TECHNICAL EXPLANATION It is anticipated that a number of intellectual advances resulting from this grant will make possible a wide range of new materials, with new structures and potential uses such as hydrogen storage alloys, magnetic compounds, and optical sensors. This research is part of the developing focus on materials science at Florida State University (FSU), and will thereby result in a broader impact on students and the scientific community. Through this project and the related establishment of a materials science curriculum at FSU, students at a variety of skill levels (high school, undergraduate, graduate, and postdoctoral) will be trained in this highly interdisciplinary field. This will enable them to interact productively with scientists in a variety of areas (such as chemistry, physics, materials science, and engineering), and to better understand the increasingly complex nature of modern science and technology.