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Van An Du, A. Sidorenko, S. Paschen, U. Schubert:
"Synthesis of Magnetic Nanostructured Iron Silicides";
Poster: 2011 Einsteins in the City, New York, USA; 14.04.2011 - 15.04.2011; in: "Abstract Booklet 2011", (2011), S. N.17.

The interest in the synthesis of iron silicide nanomaterials stems from their promising physical properties.[l] Different phases in the iron silicide System (i.e. FeSi, β-FeSi2, Fe3Si and the metastable Fe2Si, α-FeSi2, Fe5Si3) are known. The iron-rich phases Fe3Si and Fe5Si3 have ferromagnetic properties at room temperature and are thus potential materials for spintronics. Slow heating of polymer l under nitrogen resulted in α-Fe particles in a SiC/C matrix, while fast heating led to metastable ferromagnetic Fe5Si3 surrounded by a carbon layer. Formation of Fe3Si and Fe5Si3 nanoparticles derived from 2 and 3 has not yet been reported. Thermolysis of linear poly[{(dimethylsilyl)ferrocenyl}diacetylene] and poly-(ferrocenylsilane) at 850°C and 1000°C, resulted in soft magnetic nanoparticles, well distributed in a SiC/C matrix. X-ray diffraction (XRD) patterns Support the existence of Fe3Si as a crystalline phase as well as graphite. The size of the formed nanoparticles (between 10 and 500 nm) can be tuned both by the choice of polymer and the thermolysis conditions. The magnetic properties of the nanoparticles were analyzed as a function of their size by superconducting quantum interference device (SQUTD) measurements. The smallest Fe3Si nanoparticles (10-30 nm) are single magnetic domain particles.