Magnetomechanical properties of epoxy-bonded (Tb_0.3Dy_0.7)_1−xPr_xFe_1.55(0 ⩽x⩽ 0.4) pseudo-1–3 magnetostrictive composites

Abstract

Pseudo-1–3 magnetostrictive composites consisting of stabilizer (B, Co)-free, light rare earth (Pr)-containing magnetostrictive (Tb0.3Dy0.7)1−xPrxFe1.55 (0 ⩽ x ⩽ 0.4) particles with a size distribution of 10–300 µm embedded and aligned in a passive epoxy matrix using 0.5 volume fraction are fabricated. The quasistatic magnetomechanical properties of the composites are investigated and compared with their monolithic (Tb0.3Dy0.7)1−xPrxFe1.55 alloys, as a function of the Pr content x. The composites show similar qualitative trends in properties with the alloys for all x. The (Tb0.3Dy0.7)0.75Pr0.25Fe1.55 composite and alloy exhibit the smallest coercivity Hc, the largest magnetostriction λ and the highest piezomagnetic coefficient d33 due to the successful compensation for magnetocrystalline anisotropy. The (Tb0.3Dy0.7)0.75Pr0.25Fe1.55 composite demonstrates a large saturation magnetostriction λs of 793 ppm at 700 kA m−1 and a high d33 of 3.2 nm A−1 at 140 kA m−1. These values approach 81% and 85% of its alloy values at the same field levels. The good properties make the (Tb0.3Dy0.7)0.75Pr0.25Fe1.55 composite and alloy a promising magnetostrictive material system.

Anisotropy compensation and high low-field magnetostriction of epoxy/Tb1−xHox(Fe0.8Co0.2)2 composites (0.60≤x≤1.0)

“…As for the 1-3 composite, the coefficient a should have a larger value than 0.6 because of the 1 1 1 -textured particles along the measuring direction. In addition, 111 is larger than 100 for the Tb 0.25 Ho 0.75 (Fe 0.2 Co 0.8 ) 2 alloy as well as 1-3 composite has the chain structure [11], in which magnetostriction could be transferred through the interaction of the neighbor particles. Thus, it is certain that the pseudo 1-3 composite has a larger magnetostriction than the 0-3 composite has.…”

“…The molds were placed in an electromagnet with a uniform magnetic field ranging from 0 to 8 kOe along the longitudinal direction of the mold. After aligning and producing chains similar to pseudo-fiber configuration (1-3 type) [11], composites were demolded and post-cured at 90 • C for 12 h. X-ray diffraction (XRD) data were recorded at room temperature (RT) with Cu K␣ radiation in a D/max-␥A diffractrometer with a graphite crystal monochromator. High-precision XRD step scanning was performed for the (4 4 0) peak of the Laves phase and then the effect of the K␣2 radiation was removed with a standard method, in order to investigate its easy magnetization direction and magnetostriction coefficient 111 [5,12].…”

“…Most research focus on the magnetostriction value of embedding particles, the matrix character, and the composite structure such as 0-3 (the embedded phase is isolated and the second phase is connected in all three directions) or 1-3 (the embedded phase is connected in one direction) type configuration [7][8][9][10][11], while neglecting the magnetic anisotropy, magnetization nature and the EMD of the embedding particles. In fact, the magnetic anisotropy and the magnetization behavior are important factors to realize magnetostrictive properties.…”

Preparation and Magnetostriction of Epoxy-Bonded Pr(Fe_0.4Co_0.6)_1.93 Composites

“…The molds were placed in an electromagnet with and without a uniform magnetic field of 8 kOe along the longitudinal direction of the mold. After aligning and producing chains similar to pseudo-fiber (1-3 type) composites [10,11], composites were demolded and post-cured at 90°C for 12 h, and then were cut and lapped into pieces of dimensions 6×6×10 mm 3 .…”

Crystal structures and phase relationships in magnetostrictive Tb1−xDyxCo2system

“…The Laves phases RT 2 (R = Rare-earth and T = Co, Fe) have drawn lots of interests for decades due to their outstanding magnetic properties [1][2][3][4]. This alloy family was believed to crystallize in a MgCu 2 -type cubic phase, but now it is known that the magnetic phase transitions in the systems are accompanied by structural changes, and non-cubic phases are achieved at temperatures below their Curie temperature (T C ) [5][6][7][8].…”