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We report on the magnetic properties of Li-doped Mo-S nanotubes (NTs), which appears to be a realisation of a near-ideal 1D strongly correlated state in a bulk system. The material is exceptional because of its inherently extraordinarily weak coupling between 1D subunits, which is an order of magnitude weaker even than in carbon nanotube ropes. In spite of clear evidence for strong electronic correlations from a giant paramagnetic susceptibility, no transition to an ordered state is observed down to very low temperatures. Instead,the system appears to be stabilised in a paramagnetic state by fluctuations characteristic of 1-dimensional systems, with no evidence of a quantum critical point as T = 0 is approached. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

We report on two interesting applications of new nanostructured transitional- metal chalcogenide (TMC) materials based on the Mo-S-I system. We show that some new Mo-S-I materials can controllably adsorb and release relatively large amounts of Li ions in one-dimensional storage channels, and may form the basis for promising and safe new battery electrode materials. The storage capacity is found to be close to that of MoS2 NTs, comparing favourably with state-of-the-art graphite electrodes. The field emission (FE) from Mo-S-I nanostructures also appears to show very favourable characteristics compared to carbon nanotubes. The ease of processing of emitters based on TMC materials, together with the relative ease of synthesis and excellent stability suggest that the materials could be useful for e-sources in many very different electronic devices (electron microscopes, flat pannel displays, lamps etc.). © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]

Recently synthesized single-wall MoS[SUB2] nanotubes were electrochemically doped with Li and then studied by X-band electron spin resonance (ESR). We demonstrate, that on average 2.3 mole of Li per MoS[SUB2] unit can be intercalated into the bundles of MoS[SUB2] nanotubes. The ESR results show that most of the Li is intercalated into the channels between the individual nanotubes. The electronic properties of charged MoS[SUB2] nanotubes are largely determined by the defects, either by paramagnetic or topological. We found also evidence for the presence of small Li metallic particles in our sample. [ABSTRACT FROM AUTHOR]

We present STM results on single wall carbon nanotubes (SWCNTs), purified using weakly ionized and highly dissociated hydrogen plasma. The results show that, the purification process is successful in detaching the catalytic metallic particles from the SWCNT ropes. Within individual SWCNT rope we find that the metallic components are highly defective and dramatically shortened, while the semicoducting ones are with little or no defects. The defect states cause a multiple scattering of electron waves and appear as a bright spots in high-resolution STM images. [ABSTRACT FROM AUTHOR]

Using atomically-resolved scanning tunneling microscopy and spectroscopy, we probe the structure and the electronic properties of sub-nanometer MoS[SUB2] single wall nanotubes (SWNT) at room temperature. We find that, the nanotubes condense uniformly in ropes with achiral atomic structure and conical ends. Scanning tunneling spectroscopy measurements indicate a semiconducting behavior that is slightly dependent on their structural parameters. The contrast of atomic scale topographic and current STM images reveal the details of the lattice structure which allow us to identify clearly the locations of both atoms on the tube surface. By using AFM as a manipulating tool, we are able to transport or distort single MoS[SUB2] nanotubes. We will show how to artificially produce kinks, draw a circle, and write letters or numbers from MoS[SUB2] SWNT using AFM techniques. [ABSTRACT FROM AUTHOR]

It is shown that the (MOS[SUB2])[SUBn] nanotube bundles are capable of reversible lithium insertion. Comparing its properties with layered MOS[SUB2], which has been used as a positive material in the Li-ion batteries in the past [1], the new material shows promising improvements. The intercalation takes place close to the metallic lithium potential and during the insertion process, the potential decreases linearly with the amount of inserted lithium. In all, the system's characteristics indicate that (MOS[SUB2])[SUBn] nanotubes may be used as a negative electrode in rechargeable lithium batteries with some potential advantages over other systems currently in use. [ABSTRACT FROM AUTHOR]

We report on the structure and electronic properties of single wall carbon nanotube (SWNTs) tips with atomically spatial resolution. Scanning tunneling microscopy (STM) show topographic images of closed tips with a variety of geometrical structures; these include round, conical, as well as tips with a messy shape. Standing wave pattern of the charge density is observed at the tube cap which is formed due to constructive interference between the electronic states and its reflection on the nanotube tips. Atomically resolved images show asymmetry in the charge density that decay out within 6 nm away from the cap. These distinctive tip states do not exist elsewhere on the tube and are related to the presence of topological defects at tube ends. [ABSTRACT FROM AUTHOR]