Cent. Eur. J. Phys. • 10(2) • 2012 • 470-477 DOI: 10.2478/s11534-012-0013-3 Central European Journal of Physics Magnetic properties of ZnFe 2 O 4 nanoparticles Research Article Niko Guskos 1, 2 , Spiros Glenis 1 , Janusz Typek 2∗ , Grzegorz Zolnierkiewicz 2 , Pawel Berczynski 2 , Kamil Wardal 2 , Aleksander Guskos 3 , Daniel Sibera 4 , Dariusz Moszyński 4 , Witold Lojkowski 5 , Urszula Narkiewicz 4 1 Solid State Section, Department of Physics, University of Athens, Panepistimiopolis, 15 784, Greece 2 Institute of Physics, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Al. Piastow 48, 70-311 Szczecin, Poland 3 Institute of Material Sciences, Faculty of Mechanical Engineering and Mechatronics, West Pomeranian University of Technology, Al. Piastow 19, 70-311 Szczecin, Poland 4 Institute of Chemical and Environmental Engineering, West Pomeranian University of Technology, Al. Piastow 17, 70-310 Szczecin, Poland 5 Institute of High Pressure Physics, Sokolowska, 29/37, 01-142 Warszawa, Poland Received 22 October 2011; accepted 10 January 2012 Abstract: Fine particles of ZnFe 2 O 4 were synthesized by a wet chemical method in the (80 wt. % Fe 2 O 3 + 20 wt. % ZnO) system. The morphological and structural properties of the mixed system were investigated by scan- ning electron microscopy, X-ray diffraction, inductively coupled plasma atomic emission, and X-ray pho- toelectron spectroscopy. The major phase was determined to be the ZnFe 2 O 4 spinel with particle size of 11 nm. The magnetic properties of the material were investigated by ferromagnetic resonance (FMR) in the temperature range from liquid helium to room temperature. A very intense, asymmetric FMR signal from ZnFe 2 O 4 nanoparticles was recorded, which has been analyzed in terms of two Callen-lineshape lines. Temperature dependence of the FMR parameters was obtained from fitting the experimental lines with two component lines. Analysis of the FMR spectra in terms of two separate components indicates the presence of strongly anisotropic magnetic interactions. PACS (2008): 75.75.+a, 76.50.+g Keywords: ferromagnetic resonance • nanopowders © Versita Sp. z o.o. ∗ E-mail: typjan@zut.edu.pl 1. Introduction Zinc ferrite ZnFe 2 O 4 (ZFO) belongs to one of the most important iron oxides with very interesting magnetic prop- erties, which are intensively investigated from theoretical and experimental points of view [1–12]. Bulk magnetic 470