Department of complex matter

Nanomaterials: nanowires, fullerene, magnetism

INFOPACK


The synthesis of novel nanomaterials is mainly focussed on transition metal cluster nanomaterials such as MoSI nanowires. The research includes synthesis, basic characterisation, measurement of physical properties and functionalisation on the nanoscale. 

 

 

 

Nanotubes & Nanomaterials

For the synthesis and preparation the new 1D nanostuctures in the ternary molybdenum–chalcogen–halogen system in our laboratory a different chemical strategies are used like as direct synthesis from the elements and the chemical transport reaction method. The basis for all future and existing technological developments in the field of nanotechnology is the synthesis of new forms of nano-materials whose structures are on the scale of a few nanometers, 1D nanomaterials such as wires, belts ans tubes have become the focus of intensive research owing their unique applications in mescopic physich and fabrication on nanoscale devices. For the sinthesys and p reparation the new 1D nanostuctures in the our laboratory a different chemical strategies are used like as direct synthesis from the elements and the chemical transport reaction method. Research of the new synthesis is divided into two steps – in first step is target just to show that specific inorganic materials could be synthesised in form of nanowires or nanotubes and the second step is optimisation of synthesis of nanostructures. Compounds in the ternary molybdenum–chalcogen–halogen system appear to form a variety of different materials such as so-called Chevrel phases and some of ternary materials could be aligned in a class of quasi-one-dimensional materials. In 2001 a new the nano-structured material was discovered in our lab with the proposed formula MoS2I1/3. It exhibits excellent field emission properties, a large capacity for Li storage, great mechanical strength, a low shear modulus implying good tribological properties and an anomalously large paramagnetic susceptibility . However, the main problem with widespread use of MoS2I1/3 is the fact that the material is still relatively difficult to synthesize in large quantities. In 2004 we reported the discovery of a new nanowire material with the formula Mo6S3I6. The material can be synthesized in a single step, yet is functionally and structurally similar to MoS2I1/3 . It is composed of identical small-diameter nanowires, weakly bound in bundles, which can be handled in the similar way as carbon nanotubess, yet have the added advantage that they can be dispersed in different solvents including the water without using the surfactants. The sulphur atoms can be readely substituted with selenium atoms which are distributed in the resulting nanowires. Besides the production of existing materials we also try to synthesize new basic one-dimensional products on the basis of ternary system transitory metal – halcogen –halogen. Another important body of work is functionalisation experiments of these novel materials, with the aim of exploiting new chemical interferance between nanostructures and organic materials escpecilally peptides via the bridges like the gold particles.

Nanomagnetism in TDAE C60 & Related componds

Ferromagnetism of p – electron compounds forms a challenge both for theory and application. Fulleren-based charge-transfer salts have the highest Curie temperature of any known organic ferromagnet, the record being 19K. Our research includes all the steps from synthesis and magnetic characterization to crystal structure determination, which all help us to elucidate magnetic interactions on a molecular level. For more information on magnetism of fullerene-based charge-transfer complexes see recent review by Aleš Omerzu and Madoka Tokumoto here.

Some milestones in Fullerene magnetism

1995 –  Determination of the correlation between C60 molecular ordering and appearance of ferromagnetism

               in TDAE C60.

1998 –  Discovery of new ferromagnetic fullerene APhCo with the highest Curie temperature (19K) for any

               organic ferromagnet with spins on the fullerene molecules.

2000 – Determination of the C60 orientational ordering of ferromagnetic TDAE C60.

Nanomaterials: nanowires, fullerene, magnetism
Nanomaterials: nanowires, fullerene, magnetism