Dynamic magnetoelastic properties of epoxy-bonded Sm_(0.88)Nd_(0.12)Fe_(1.93) pseudo-1-3 negative magnetostrictive particulate composite

摘要

Pseudo-1-3 negative magnetostrictive particulate composite is prepared by embedding and aligning light rare earth (Sm and Nd)-based negative magnetostrictive Sm_(0.88)Nd_(0.12)Fe_(1.93) particles with randomly distributed sizes of 10-180 μm in a passive epoxy matrix using a particle volume fraction of 0.5. The dynamic magnetoelastic properties of the composite are investigated as a function of both magnetic bias field and frequency under a constant magnetic drive field. The dynamic relative permeability (μ_(r33)) exhibits a flat frequency response with no observable dispersion at all bias field levels, except for the fundamental shape resonance range of 40-50 kHz. The free (μ_(r33)~T) and clamped (μ_(r33)~S) relative permeabilities attain their maximum values at low bias field levels of ≤10 kA/m because of the relatively easy 180° domain-wall motion. The elastic modulus at constant magnetic field strength (E_3~H) and that at constant magnetic flux density (E_3~B) show a maximum negative-AE effect, accompanying a maximum dynamic strain coefficient (d_(33)) of-2 nm/A, at about 100 kA/m due to the maximum motion of non-180° domain walls.