Title :
Dynamic magnetic behaviour of interacting γ-Fe2O 3 nanoparticles dispersed in epoxy resin
Author :
Mira, J. ; López-Pérez, J.A. ; Rivas, J. ; López-Quintela, M.A. ; Caciuffo, R. ; Rinaldi, D. ; Fiorani, D.
Author_Institution :
Dept. of Appl. Phys., Santiago de Compostela Univ., Spain
fDate :
9/1/1997 12:00:00 AM
Abstract :
The dynamical behaviour of γ-Fe2O3 particles synthesized by a microemulsion route, with an average diameter of 7 nm and dispersed in an epoxy-resin at different concentrations, has been investigated by a.c. magnetic susceptibility measurements (8<f (Hz)<1000). For the most diluted sample, the frequency dependence of the temperatures of the maximum of the in-phase susceptibility follow an Arrhenius law with physical τ0 value (10-10 s). Unphysical, much lower values are found for samples consisting of interacting particles. The results are explained by accounting for the change of interparticle distance and number of particle neighbours
Keywords :
ferrites; filled polymers; iron compounds; magnetic particles; magnetic relaxation; magnetic susceptibility; microemulsions; nanostructured materials; superparamagnetism; 7 nm; 8 to 1000 Hz; AC magnetic susceptibility measurements; Arrhenius law; Fe2O3; average diameter; concentrations; dynamic magnetic behaviour; epoxy resin; frequency dependence; in-phase susceptibility; interacting γ-Fe2O3 nanoparticles; interparticle distance; magnetic nanoparticles; microemulsion route; most diluted sample; particle neighbours; superparamagnetic relaxation; Dispersion; Magnetic field measurement; Microstructure; Nanoparticles; Particle measurements; Performance evaluation; Resins; Shape control; Temperature; Water heating;
Journal_Title :
Magnetics, IEEE Transactions on
