Nanoforum - Nanotech Regulatory Document Archive

where the building units are formed by chemically identical nanoparticles
and/or nanocapsules having core/shell structure. Of particular interest is to
better understand the effects of the variation of grain sizes and the
intergranular distances as well as the chemistry of the constituent phases on
the magnetic behaviour in a wide range of applied fields and temperatures.
The aims of a potential FP6 project can be outlined in the following way:
• Optimisation of the alloys composition and the preparation methods in order to
obtain nanostructured magnetic materials with improved functional
properties
• Study the effects of residual amorphous matrix as well as the grain sizes and
intergranular distances on the character and intensity of magnetic
coupling between grains and on the magnetic behaviour versus
temperature in investigated nanocrystalline magnetic materials
• Study the magnetocaloric behaviour in selected nano-composite materials
• Better understand the influence of interfaces on the magnetic properties
of investigated nanostructured materials
Preparation of bulk nanocrystalline materials by milling
Address: Slovak Academy of Sciences, Institute of Geotechnics, Watsonova 45, 043 53
Kosice, Slovak Republic
Contact: Prof. Dr. Peter BALAZ
Phone: +421 55 63 307 90
E-mail: balaz@saske.sk
Research subject for a potential FP6 project:
Nanocrystalline materials are single-phase or multi-phase materials, the
crystal size of which is of the order of a few (typically 1-100) nanometers
in at least one dimension. Nanocrystalline materials have been synthesised
by a number of techniques starting from the vapour phase (e.g.inert gas
condensation), liquid phase (e.g. rapid solidification), and solid state (e.g.
mechanical alloying). Mechanical alloying is a solid-state powder processing
technique involving repeated welding, fracturing, and rewelding of powder
particles in a high-energy mill. Grain sizes with nanometer dimensions have
been prepared in form of amorphous alloys, nanostructured metal nitrides,
metal hydrides, metal carbides, metastable materials and nanocomposite
materials.
The possibilities of solid-state mechanochemical reductions (displacement
reactions) as well as solidstate mechanochemical reactions in order to
prepare novel nanocrystalline materials are currently studied in our
Department. The mechanochemical reduction of copper sulphides with iron was
induced in a planetary mill. The transformation of copper sulphides, the
synthesis of cubic FeS and its transformation to the hexagonal form are
215