Dynamic magnetoelastic properties of epoxy-bonded Sm_0.88Nd_0.12Fe_1.93pseudo-1-3 negative magnetostrictive particulate composite

Pseudo-1-3 negative magnetostrictive particulate composite is prepared by embedding and aligning light rare earth (Sm and Nd)-based negative magnetostrictive Sm0.88Nd0.12Fe1.93particles with randomly distributed sizes of 10-180 μm in a passive epoxy matrix using a particle volume fraction of0.5. 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 (μr33T) 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 (μr33T) and clamped (μr33T) 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 (E3H) and that at constant magnetic flux density (E3B) show a maximum negative-E effect, accompanying a maximum dynamic strain coefficient (d33) of -2 nm/A, at about 100 kA/m due to the maximum motion of non-180 domain walls.