Dynamic magnetomechanical properties of epoxy-bonded (Tb0.3Dy0.7)1–xPrxFe1.55 (0 ≤ x ≤ 0.4) pseudo-1–3 magnetostrictive composites

Pseudo-1–3 magnetostrictive composites of 0.5 volume fraction are fabricated by embedding and aligning stabilizer (B, Co)-free, light rare earth (Pr)-contained magnetostrictive (Tb0.3Dy0.7)1–xPrxFe1.55 (0 ≤ x ≤ 0.4) particles with a size distribution of 10–300 μm in a passive epoxy matrix. The dynamic magnetomechanical properties of the composites with different Pr content x are investigated as a function of both bias field (=10–200 kA/m) and frequency (=25 Hz–70 kHz). The composites show similar qualitative trends in properties for all x   with no frequency dispersion effect except for the resonance range. The dynamic relative permeability μr33T demonstrates a decreasing trend with increasing x   for the whole range of bias field due to the weakening of saturation magnetization with increasing Pr content. The two elastic moduli E3H and E3B, which result in negative-ΔE with maximum dynamic strain coefficient d33 and dynamic magnetomechanical coupling coefficient k33 near 140 kA/m bias in all composites, decrease with increasing x for all biases owing to the increasing compliance contribution from Pr. The (Tb0.3Dy0.7)0.75Pr0.25Fe1.55 composite exhibits the largest d33 and k33 at 140 kA/m bias as a result of the compensation for magnetocrystalline anisotropy.