Research/Forschung

Research work concentrates on molecular nanostructures,  functionalization of molecular nanostructures,
dimensionality and quantum size effects, template grown nanomaterial, nanoreactors, etc.
Examples are:
fullerenes, fullerene derived materials, nanotubes, nanostructured carbon systems, nanodiamond
nanodiamond nanocoatings, etc.
 

Information about research in the lab:

Current research projects:

FULPROP :         TMR project, more links to the FULPROP homepage
                                                local links to the FULPROP research and training activities at the IMP
FUNCARS:         IHP project, more, links to the FUNCARS homepage
                                               local  links to the FUNCARS research and training activities at the IMP
MEA-PPNCD :   GROWTH project, more
NANOCARB :    INTAS project, more links to the NANOCARB homepage
                                                    local links to the NANOCARB research and training activities at the IMP
NANOTEMP:      TMR project, more links to the NANOTEMP homepage
                                                    local links to the NANOTEMP research and training activities at the IMP
VDWAALS:        project supported by FWF, more links to the project homepage
RÖHRCHEN:      project supported by FWF, more links to the project homepage
MASKEN:           project supported by FWF, more links to the project homepage
 

Description of research work:

Our current work is mostly in the field of nanomaterials. The Nanotech-Now site has lots of useful infos and links about this subject in general.

The discovery of the quantum Gyroscop:

Details can be found here.

Fullerenes:

Fullerenes are molecular cages consisting of only carbon atoms. The arrangement of the atoms is almost exclusively in the form of hexagons and pentagons. 12 pentagons and 20 hexagons make the most famous C60 cage. This cage was first identified experimentally by H.W. Kroto, R.E. Smalley, and R.F. Curl in 1985. These researchers were awarded the Nobel prize in Chemistry for their discovery in 1996, after W. Krätschmer and D. Hufman had developed a technique for the growth of fullerenes in large quantities.
C60 fullerenes are the most stable and the most abundant species. C60 crystals exhibit several interesting phase transitions and they are photophysically active in several ways.  They can be doped to a metallic and even superconducting state. Transition temperatures in the latter matrerial are as high as 30 K.
 
 

  C60 fullerene

 


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Polymeric Fullerenes:

A new class of fullerenic materials!
Fullerenes of the above type can polymerize to a covalently connected string, pane, or even threedimensional arrangement of individual molecules. The connection can be either by one single bond between carbons on neighboring cages or by a pair of single bonds between the cages.
Doped species as well as undoped material is available. The new polymers can be semiconducting or metallic but no superconductivity has been observed sofar.
Polymerization has been reported for C60 but also for C70 cages.
Threedimensional polymerization can leed to ultrahard material, material which is harder than diamond.
Doping of the polymer can be performed by intercalation of electron donors inbetween the cages but also by substitution of carbon atoms by donors on the cage. For dimers intercalation doped systems and substitution doped systems exhibit very similar electronic properties.
Doped polymers can have very unusual magnetic properties.

Dimeric (C59N)2

 


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Nanocage Encapsulates:

Metallic (transition metals or rare earths) or nonmetallic atoms (N, P, He) can be encapsulated into the fullerene cages. Such materials exhibit an other class of new fullerenic materials. The endohedral chemistry of such systems was found to be quite different to the conventional exohedral chemistry.
 

    Endohedral metallofullerene Sc3@C84

 


 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Carbon Nanotubes:

Carbon nanotubes are rolled up sheets of graphene where the geometry for the rolling up process is determined by a lattice vector (folding vector or Hamada vector) of the plane. The two components of the lattice vector, expressed as integers (n,m), determine the geometry of the tubes like its diameter and helicity and its electronic structure.  Typical values of the former are 1.4 nm. With respect to the latter semiconducting tubes, narrow gap tubes and metallic tubes are known. The extension of the described systmes is exactly ondimensional with respect to its periodicity in space. As a consequence the electronic density of states exhibits well expressed Van Hove singularities.
Tubes of the above type are called single wall carbon nanotubes (SWCNTs). In contrast tubes consist often of a set of concentrically arranged SWCNTs. In this case the tubes are called multiwall carbon nanotubes (MWCNTs). Single wall carbon nanotubes are usually aggregated into bundles with a hexagonal lattice structure in the cross section but with a highly incommensurate arrangement of the tubes in the bundle. Similarly, for the MWCNTs the concentic tubes are necessarily arranged in an incommensurate manner as the have different diameter and different helicity.
Electronic and latticdynamical properties if the tubes exhibit macroscopic quantum effects which, among several other interesting technical properties, triggered the dramatically growing interest in such systems.
 

  A single wall carbon nanotube

 

Results of electronic density of states (DOS) calculations are available by following this link.


 
 
 
 
 
 
 
 
 
 
 
 

Nanocrystalline Diamond:

Nanocrystalline diamond can exhibit optimum properties for many applications in high technology electronics, heat technology or mechanical technology. Low wear and low friction are obtained for ultra smooth films. New technologies are to be developed for the preparation of thin films by CVD with very good lamination to substrates such as cutting tools, bearings, or packaging material. .
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Stand 22.11. 2001
Betreuung durch Hans Kuzmany