FP6 priority

1.1.3   Nanotechnologies and Nanosciences, Knowledge-based Multifunctional Materials and New Production Processes and Devices

1.3.1

Title of the proposal

Nanoscale Complex Oxides Prepared by High-Energy Milling Method: Structural Disorder, Spin Configuration and Thermal Stability

Institute

Slovak Academy of Sciences, Institute of Geotechnics
Watsonova 45, SK-04353 Kosice, Slovak Republic

Contact

Research subject for a potential FP6 project

The character of the mechanically induced cation redistribution, the nature of metastability, and the origin of mechanically induced changes in magnetic properties of nanoscale mechanically activated and of mechanosynthesized complex oxides (with spinal and perovskite structure) will be elucidated. To establish a better basis of the “strain design”, the disorder - magnetic property relationship in nanosized milled complex oxides will be compared with that in the strained nanoscale oxides prepared by a low-temperature technique (e.g. coprecipitation, sol-gel method). Attention will be concentrated on the generalization of the compiled data on the disorder (cation redistribution, spin canting, etc.) for nanoscale iron-containing spinals and perovskites. The presence of systematic trends in the extent of the mechanically induced disorder and of the change in spin configuration will be examined. Attention will also be focused on the explanation of an origin of spin canting in nanosized complex oxides (spinels and perovskites). The range of thermal stability of mechanically induced metastable states and the mechanism of their relaxation into a low-energy state will be determined.

Recent international cooperation of the research team

Institute of Physical and Theoretical Chemistry, Technical University of Braunschweig, Braunschweig, Germany; Institute of Applied Chemistry, Berlin-Adlershof, Germany; Institute of Solid State Chemistry and Mechanochemistry, Russian Academy of Sciences, Novosibirsk, Russia; Department of Materials Engineering, Ben-Gurion University of the Negev, Beer-Sheva, Israel; Laboratory of Industrial Physical Chemistry, Keio University, Yokohama, Japan; Institute of Inorganic Chemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Proposer´s relevant publications related to the research subject

. Sepelak, D. Schultze, F. Krumeich, U. Steinike, K.D. Becker, Mechanically Induced Cation Redistribution in Magnesium Ferrite and Its Thermal Stability. Solid State Ionics 141-142 (2001) 677;
V. Sepelak, D. Baabe, F.J. Litterst, K.D. Becker, Structural Disorder in the High-Energy Milled Magnesium Ferrite. J. Appl. Phys. 88 (2000) 5884;
V. Sepelak, K.D. Becker, Mossbauer Studies in the Mechanochemistry of Spinel Ferrites. J. Mater. Synth. Proces. 8 (2000) 155;
V. Sepelak, S. Wißmann, K.D. Becker, Magnetism of Nanostructured Mechanically Activated and Mechanosynthesized Spinel Ferrites. J. Magn. Magn. Mater. 203 (1999) 135.
V. Sepelak, U. Steinike, D.Chr. Uecker, S. Wißmann, K.D. Becker, Structural Disorder in Mechanosynthesized Zinc Ferrite. J. Solid State Chem. 135 (1998) 52.