材料期刊网

Pseudo-1-3 negative magnetostrictive particulate composite is prepared by embedding and aligning light rare earth (Sm and Nd)-based negative magnetostrictive Sm0.88Nd0.12Fe1.93 particles with randomly distributed sizes of 10-180 mu m 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 (mu(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 (mu(T)(r33)) and clamped (mu(S)(r33)) relative permeabilities attain their maximum values at low bias field levels of <= 10 kA/m because of the relatively easy 180 degrees 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-Delta E 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 degrees domain walls. (C) 2012 American Institute of Physics. [doi:10.1063/1.3679045]