Particles and fields physics Magnetic fluids Ferrimagnetic resonance Magnetic anisotropy Damping parameter Precessional decay time
P.C. Fannin, C.N. Marin, K. Raj, C. Couper, P. Barvinschi, An experimental study of the dynamic properties of nanoparticle colloids with identical magnetization but different particle size, Journal of Magnetism and Magnetic Materials, 324, 21, 2012, 3443 - 3447
Journal of Magnetism and Magnetic Materials 324 21
Measurements of the frequency dependent complex magnetic susceptibility, χ(ω)=χ′(ω)−iχ″(ω), have been used to determine the dynamic properties of three specially prepared 400 G (0.04 T) magnetic fluids. The samples, denoted by sample 1, sample 2 and sample 3, consisted of magnetite particles of mean diameter 6.4 nm, 7.5 nm and 9 nm respectively and were identical in terms of carrier liquid, surfactant and particle material.
From polarised ferromagnetic measurements, the anisotropy field, HA, the Landau-Lifshitz damping parameters, α, and the precessional decay time, τ0 of the particles were determined. The results show that the HA value for sample 3 was almost twice that of sample 1 and 2, thus confirming that the smaller the particle size, the lower the value of HA. The damping parameter, α, was found to be 0.174 (for sample 1), 0.18 (for sample 2) and 0.16 (for sample 3). The values determined for the precessional decay time, τ0 were 1.197×10−9 s, 1.157×10−9 s and 0.789×10−9 s, for samples 1, 2 and 3 respectively.
Please note: There is a known bug in some browsers that causes an
error when a user tries to view large pdf file within the browser window.
If you receive the message "The file is damaged and could not be
repaired", please try one of the solutions linked below based on the
browser you are using.
Items in TARA are protected by copyright, with all rights reserved, unless otherwise indicated.