Lanthanide-based functional misfit-layered nanotubes
Leela S. Panchakarla, Ronit Popovitz-Biro, Lothar Houben, Rafal E. Dunin-Borkowski, and Reshef Tenne
A new family of nanotubes composed of misfit layered compounds of the general formula [(MX)1+x]m[TX2]n, where M can includePb,Sb,rareearths; T=Cr,Nb,andX=S, Se was established. Alternating superstructures of (MX)1+x and TX2 could layers be merged into tubular geometry even though each sub-system alone is not necessarily a layered or a stable compound. A simple chemical method is used to synthesize these complex nanotubes. The synthesis procedure involves a high temperature transformation of the ternary oxide (hydroxide mixture) into the respective sulfide. Quaternary nanotubular structures formed by partial substitution of the lanthanide atom in nanotubes by other elements are also confirmed. The driving force and mechanism of formation of these nanotubes is investigated by systematic temperature and time-dependent studies. Fascinatingly, any desired combination of insulators, semiconductors, metals, and superconductors with well-defined ff optical transitions and magnetism can be made by smart combination of elements. The resulting materials may find applications in fields that include thermoelectrics, light emitters, composites, magnetic materials, and catalysts and address fundamental physical issues in reduced dimensions.
Leela S Panchakarla, Ronit Popovitz-Biro, Lothar Houben, Rafal E Dunin-Borkowski, and Reshef Tenne: Lanthanide-based functional misfit-layered nanotubes, Angewandte Chemie International Edition 53 (2014) 6920-6924.