Low Concentration Effect of Fe3O4 and Fe3C Magnetic Nanoparticles in Non-Magnetic Matrix on the FMR Spectra

T. Bodzionya, N. Guskosa,b, Z. Roslaniecc, U. Narkiewiczd, M. Kwiatkowskac and M. Maryniaka aInstitute of Physics, Szczecin University of Technology, al. Piastów 17, 70-310 Szczecin, Poland bSolid State Section, Department of Physics, University of Athens, Panepistimiopolis, 15 784, Greece cInstitute of Material Engineering, Szczecin University of Technology, al. Piastów 17, 70-310 Szczecin, Poland dDepartment of Chemical Engineering, Szczecin University of Technology, al. Piastów 17, 70-310 Szczecin, Poland

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Received: 24 04 2005;

PTMO-block-PET polymer filled with a low concentration (0.1 wt.%) of binary magnetic system: magnetite (Fe3O4) and iron carbide (Fe3C) with carbon (C) was prepared. Characterization of the sample was done by using X-ray diffraction and scanning electron microscopy methods. Temperature dependence of the FMR spectra was carried out in the 10-300 K temperature range. The extraordinary temperature dependence behaviour of FMR spectra was recorded. The FMR spectra were fitted by two Lorentzian lines originating from magnetite and iron carbide. The anomalous behaviour of FMR spectra below 100 K could be explained by the skin effect or by the freezing of the matrix benzene rings at about 115 K. The temperature dependence of the g parameter below 75.5 K (opposite shift of the resonance field to usually observed) was interpreted as a result of strong antiferromagnetic interaction of some portion of agglomerates.

DOI: 10.12693/APhysPolA.108.297 PACS numbers:76.50.+g, 75.70.-i