Fundamental Studies of Novel Inorganic Fullerenes

Colorado State University, Fort Collins CO

Investigators

Abstract

The focus of this project is to study a recently discovered class of inorganic closed shell nanostructures, composed of nested octahedra of layered-structure transition metal dichalcogenides that are expected to have discrete stoichiometries. The synthesis and properties of the molybdenum disulfide and -diselinide nano-octahedra as well as other layered materials such as tantalum disulfide, niobium diselinide, tungsten disulfide, molybdenum diselinide, and molybdenum diteluride, produced by laser ablation of the bulk material will be investigated. The currently used laser ablation method for "inorganic fullerenes" (IF) production will be optimized, and other methods for producing these novel structures such as are discharge will be explored. The structural and electronic properties of the novel IF phases will be investigated with scanning probe microscopies. Individual IF particles will be imaged and their electronic properties measured via tunneling spectroscopy, both under ambient conditions and as a function of temperature in an ultrahigh vacuum environment. The electronic density of states, measured by tunneling spectroscopy, will determine if these new materials are semiconducting or metallic. Additionally these properties will be studied as a function of size, shape and composition of the IF structures. The IF materials are potentially useful as lubricants due to a combination of low rolling and sliding friction. The intrinsically monodisperse semiconducting IFs will be useful for quantum dot applications. %%% Both graduate and undergraduate students working on this project will be exposed to the excitement of discovery associated with opening a new area of solid state chemistry and materials science. They will get experience with many different synthesis, separation and characterization techniques and learn to communicate their results to each other and the scientific community. The resulting interdisciplinary training will make them well prepared for future positions in academia, industry and government laboratories in areas of chemistry, materials science and nanotechnology.