Physical Properties of Tubular Structures of Misfit Layer Compounds

Several nanotubular structures from misfit layer compounds were reported in recent years. Misfit layer compounds (MLC) consists of a stacking of two alternating two-dimensional atomic layers with different crystal structures. The mismatch between the alternating layers and the seaming of the dangling bonds at the edges drives them to form a variety of tubular structures. These tubular structures are great candidates to present interesting physical properties which were not investigated hitherto. One of the MLC NTs synthetized by our group consist of layers of LaS and TaS₂ layers stacked and rolled together. TaS₂ is an extremely interesting material since it shows a wide variety of particular physical effects including superconductivity, charge-density-waves and Mott insulation phases. The intercalation of the LaS result in a charge transfer to the TaS₂. The latter, together with the low dimensionality of the nano-structure constitute a ripe field for the study of interesting physical phenomena in 1D. The main goal of the research was to incorporate single MLC nano-tubes (NTs) into electrical devices, using advanced lithographic technics, and in that way to learn about their electrical behavior. The research includes two-probe electrical measurement at room and low temperatures showing a semi-metallic behavior. Hall and Raman measurements measured with individual nanotube devices will be reported as well.