PHYSICAL PROPERTIES OF TUBULAR STRUCTURES OF MISFIT LAYERED COMPOUNDS

Several nanotubular structures from misfit layered compounds were reported in recent years. Misfit layered 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 candidates to present interesting physical properties, which were not investigated hitherto. One of the MLC nanotubes 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 layers result in a charge transfer to the TaS₂ layers. The latter, together with the low dimensionality of the nanostructure constitute an interesting system for the study of intriguing physical phenomena in 1D. The main goal of the research was to incorporate single MLC nanotubes (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 at low temperatures, showing a semi-metallic behavior. Hall and Raman measurements measured with individual nanotube devices will be reported as well.