Ultrasensitive magnetostrictive responses at the pre-transitional rhombohedral side of ferromagnetic morphotropic phase boundary

Abstract

The morphotropic phase boundary (MPB) has been utilized extensively in ferroelectrics and recently been extended to ferromagnets, especially for the magnetostrictive materials. Here, guided by phenomenological theories and phase-field simulations, we proposed a design strategy for obtaining the ultrasensitive magnetoelastic response at the pre-transitional rhombohedral side of ferromagnetic MPB, by further flattening the energy landscape while maintaining large intrinsic magnetostriction. To validate this, we judiciously introduced the light-rare-earth-based Tb 0:1 Pr 0:9 system to the Co-doped Tb 0:27 Dy 0:73 Fe 2 alloy, as Tb 0:1 Pr 0:9 is an anisotropy compensation system with large intrinsic strains and the transition metal dopant of Co tends to optimize the magnetostriction. Phase-field modeling was used to determine the detailed magnetic domain evolution of the investigated multi-component Laves phase compounds, the results of which were compared with experimental results. At room temperature, an ultrahigh magnetoelastic response d 33 was found in Tb 0:253 Dy 0:657 Pr 0:09 ðFe 0:9 Co 0:1 Þ 2 recompensation system especially at low fields, which is superior to that of the commercial Tb 0:27 Dy 0:73 Fe 2 (Terfenol-D) polycrystal. The ultrahigh magnetostrictive sensitivity, together with low raw material cost makes it one of the strongest candidates for magnetostriction applications.

Recent Advances in Magnetostrictive Tb-Dy-Fe Alloys

“…The 440 C XRD profiles and magnetostriction of (Tb 0.2 Pr 0.8 ) x Dy 1−x Fe 1.93 (x = 0.00, 0.05, 0.10, 0.20 and 0.30) single Laves phase compounds synthesized by high-pressure annealing are shown in Figure 7 [41]. Based on the consideration of anisotropy compensation and thermodynamic energy flattening, a rare-earth sublattice was designed, and the ternary composition phase diagram and the minimum anisotropy composition are shown in Figure 8 [42]. 0.6) was composed of a MgCu2-type C15 cubic Laves phase, with a small amount of a PuNi3-type phase and rare-earth-rich phase [11].…”

“…Based on the consideration of anisotropy compensation and thermodynamic energy flattening, a rare-earth sublattice was designed, and the ternary composition phase diagram and the minimum anisotropy composition are shown in Figure 8 [42]. [42]. Reprinted with permission from Ref.…”

“…Similar to ferroelectrics, it was believed that the flattening of thermodynamic energy should lead to the sensitive response of the ferromagnetic phase. Through the introduction of Tb 0.1 Pr 0.9 to Co-doped Tb 0.27 Dy 0.73 Fe 2 alloy, Hu et al explored the feasibility of this assumption through phase-field simulation [42]. They provided a feasible strategy for the design of an ultrasensitive magnetostrictive response with minor metastable orthorhombic phases as bridging domains, as shown in Figure 20.…”

“…They provided a feasible strategy for the design of an ultrasensitive magnetostrictive response with minor metastable orthorhombic phases as bridging domains, as shown in Figure 20. Energy analysis for the samples with 0.00 ≤ x ≤ 0.20 [42]. Reprinted with permission from ref.…”

“…The calculated spin-orientation diagram reproduced the experimental results for the [111] and [100] easy directions, as shown in Figure 21. [42]. Reprinted with permission from ref.…”