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 μr 33Tdemonstrates 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 E3Hand E3B, which result in negative-ΔE with maximum dynamic strain coefficient d33and dynamic magnetomechanical coupling coefficient k33near 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)0.75Pr0.25Fe1.55composite exhibits the largest d33and k33at 140 kA/m bias as a result of the compensation for magnetocrystalline anisotropy.