Abstract: Highly ordered Ge films are prepared directly on single crystal Si substrates by applying an aqueous coating solution having Ge-bound polymer onto the substrate and then heating in a hydrogen-containing atmosphere. A coating solution was prepared by mixing water, a germanium compound, ethylenediaminetetraacetic acid, and polyethyleneimine to form a first aqueous solution and then subjecting the first aqueous solution to ultrafiltration.

Abstract: Composite structures of carbon nanotubes (CNTs) and metal carbides include a helical nanotube/carbide composite fiber, and a film. The composite fiber was prepared by pulling/twisting carbon nanotubes from an array of nanotubes to form an as-spun fiber and soaking it a metal precursor solution, and then heating it under a reducing atmosphere with a carbon source. The composite fiber had a higher tensile strength, a higher conductivity, and a higher tensile modulus than the as-spun fiber. A composite structure in the form of parallel ribbons of aligned carbon nanotubes embedded in a film of NbC showed an enhanced conductivity along the CNT axial direction, and improved superconducting properties. The enhanced upper critical field of NbC/CNT suggested that the inclusion of CNTs in the NbC matrix reduced the coherence length of the NbC. Nanomechanical testing also demonstrated the potential for enhanced fracture toughness of NbC/CNT composites.

Abstract: A coating solution including a polymer and a metal selected from scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, boron, aluminum and silicon can be deposited on a substrate and then exposed at elevated temperature to a reducing atmosphere including a gaseous carbon source. Solvent evaporates and the polymer decomposes and a metal carbide film forms on the substrate. Metal carbide films of titanium carbide, vanadium carbide, niobium carbide, tantalum carbide, tungsten carbide, silicon carbide, and several mixed carbides were prepared. X-Ray diffraction patterns of metal carbide films provide evidence of a highly ordered structure and excellent alignment with the substrate. A composite film of niobium carbide and carbon nanotubes was also prepared.

Abstract: Highly ordered Ge films are prepared directly on single crystal Si substrates by applying an aqueous coating solution having Ge-bound polymer onto the substrate and then heating in a hydrogen-containing atmosphere. A coating solution was prepared by mixing water, a germanium compound, ethylenediaminetetraacetic acid, and polyethyleneimine to form a first aqueous solution and then subjecting the first aqueous solution to ultrafiltration.