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Ferromagnetic resonance from nanoparticle agglomerates in nonmagnetic matrices
|Nikolaos Gouskos 3, Janusz Typek 2, Urszula Narkiewicz 1,4, Michał Maryniak 2, K Aidinis 3|
1. Technical University of Szczecin, Pulaskiego 10, Szczecin 70-322, Poland
Samples of α-Fe and Fe3C nanoparticle agglomerates dispersed at different concentrations in various nonmagnetic matrices have been prepared. The agglomerates have been characterized by XRD and SEM spectroscopy. Magnetic resonance measurements of the samples have been carried out at different temperatures in the 4-300 K range. An intense and broad magnetic resonance absorption line has been recorded at different magnetice resonance fields for various matrices. With decreasing temperatures the resonance field has shifted and the intensity and the linewidth of that resonance line have displayed an unusual behavior. The resonance line could be fitted by a superposition of two Lorentzian-shape lines: one centered at lower magnetic field and the other placed at higher resonance magnetic field showing strongly decreased integrated intensity with decreasing temperatures. It is suggested that the magnetic resonance condition depends essentially on the internal magnetic field. This phenomenon is stronger for the Fe nanoparticle agglomerates than for Fe3C, for which the Neel temperature is higher. The magnetic exchange interaction between spins essentially influences the above processes.
Presentation: oral at E-MRS Fall Meeting 2004, Symposium I, by Nikolaos Gouskos
See On-line Journal of E-MRS Fall Meeting 2004
Submitted: 2004-04-29 09:46 Revised: 2009-06-08 12:55