Dynamic magnetoelastic properties of Tb_xHo_0.9−xNd_0.1(Fe_0.8Co_0.2)_1.93/epoxy composites

Abstract

TbxHo0.9−xNd0.1(Fe0.8Co0.2)1.93/epoxy (0 ⩽ x ⩽ 0.40) composites are fabricated in the presence of a magnetic field. The structural and dynamic magnetoelastic properties are investigated as a function of both magnetic bias field Hbias and frequency f at room temperature. The composites are formed as textured orientation structure of 1–3 type with 〈1 0 0〉 preferred orientation for x ⩽ 0.10 and 〈1 1 1〉-orientation for x ⩾ 0.25. The composites generally possess insignificant eddy-current losses for frequency up to 50 kHz, and their dynamic magnetoelastic properties depend greatly on Hbias. The elastic modulus (E3H and E3B) shows a maximum negative ΔE effect, along with a maximum d33, at a relatively low Hbias ~ 80 kA/m, contributed by the maximum motion of non-180° domain-wall. The 1–3 type composite for x ⩾ 0.25 shows an enhanced magnetoelastic effect in comparison with 0 to 3 type one, which can be principally ascribed to its easy magnetization direction (EMD) towards 〈1 1 1〉 axis and the formation of 〈1 1 1〉-texture-oriented structure in the composite. These attractive dynamic magnetoelastic properties, e.g., the low magnetic anisotropy and d33,max as high as 2.0 nm/A at a low Hbias ~ 80 kA/m, along with the light rare-earth Nd element existing in insulating polymer matrix, would make it a promising magnetostrictive material system.

Enhanced magnetoelastic performance in Pr/Mn-doped Laves phase (Tb,Ho)Fe2 compounds

“…As a typical magnetostrictive intermetallic compound with C15 Laves structure, TbFe 2 stands out because of its largest magnetostriction to date, exhibiting at the room temperature λ 111 as large as 2460 ppm. Yet, a huge magnetocrystalline anisotropy energy exists, the first order constant K 1 reaches a large value of -76 × 10 6 erg/cm 3 , which has been a longstanding drawback in practical applications, because then large magnetic fields are required to saturate the magnetization and magnetostriction. Indeed, the high anisotropy should be reduced, and simultaneously a large magnetostriction should be retained.…”

“…Indeed, the high anisotropy should be reduced, and simultaneously a large magnetostriction should be retained. Introducing other rare-earth elements (RE) to compensate the anisotropy of Tb 3+ , whilst maintaining the large magnetostriction, is one of the effective methods, and subsequently, the Tb-Dy-Fe alloys (known as Terfenol-D) and Tb-Ho-Fe * E-mail: liujinjun1@nbu.edu.cn alloys, have been developed and widely used for both sensing and actuation [1][2][3]. However, the raw materials, such as heavy RE metals (e.g.…”