FP6 priority
1.1.3   Nanotechnologies and Nanosciences, Knowledge-based Multifunctional Materials and New Production Processes and Devices
Title of the proposal

Preparation of bulk nanocrystalline materials by milling

Slovak Academy of Sciences, Institute of Geotechnics
Watsonova 45, 043 53 Kosice, Slovak Republic
Prof. Dr. Peter BALAZ
+421 55 63 307 90

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 synthesized by a number of techniques starting from the vapor 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 solid-state 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 associated with the primary mechanochemical reduction. Platelets of Cu/FeS nanoparticles are formed with the average grain size of the freshly formed copper are between 10-25 nanometers. The novel processes of nanocrystalline sulphides synthesis that is stimulated by their extensive use in infrared optoelectronics for manufacturing IR lasers and detectors are now strongly focused in our Department.

Recent international cooperation of the research team

Technical University, Lyngby, Denmark; Technical University of Liege, Belgium; University of Maryland Baltimore County, Baltimore, USA; Keio University, Yokohama, Japan; J. Heyrovsky Institute of Physical Chemistry, Prague, Czech Republic

Proposerīs relevant publications related to the research subject

1. P. Balaz, M. Valko, E. Boldizarova and J. Briancin - Properties and reactivity of Mn-doped ZnS nanoparticles. Materials Letters 2002 (accepted for publication).
2. P. Balaz, L. Takacs, T. Ohtani, D.E. Mack, E. Boldizarova, V. Soika and M. Achimovicova -Properties of a new nanosized tin sulphide phase obtained by mechanochemical route. J.of Alloys and Compounds 2002 (accepted for publication).
3. P. Balaz, L. Takacs, J.Z. Jiang, V. Soika and M. Luxova - Mechanochemical reduction of copper sulphide. J. of Metastable and Nanocryst. Materials 13 (2002) 257-262.
4. P. Balaz and B. Plesingerova - Thermal properties of mechanochemically pretreated precursors of BaTiO3 synthesis. J. Thermal Anal. Calorim. 59 (2000) 1017-1021.
5. P. Balaz, T. Ohtani, Z. Bastl and E. Boldizarova – Properties and reactivity of mechanochemically synthesized tin sulfides. J. Solid State Chemistry 144 (1999) 1-7.
6. P. Balaz, A. Mockovciakova, E. Boldizarova and J. Ficeriova - Physical and chemical changes of sulphides during intensive grinding in organic liquids. Powder Technol. 98 (1998) 74-78.