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

Magnetostrictive Tb_xHo_0:8−xPr_0:2Fe_1:8Mn_0:1 (0 ⩽ x ⩽ 0.20) alloys are prepared by arc-melting and subsequent annealing. The dopant of Pr/Mn introduced into RFe₂ compounds effectively stabilizes the forming of single C15 Laves phase at ambient pressure. The easy magnetization direction (EMD) varies when Tb content increases, which is accompanied by a crystalstructural transition. EMD lies along ‹1 0 0› axis for x ⩽ 0.05, rotating to ‹1 1 1› axis for x ⩽ 0.12, with a tetragonal symmetry changing to a rhombohedral one. Magnetocrystalline-anisotropy compensation is obtained with the optimized composition of x = 0.12, shifting to the Tb-poor side in comparison to Pr/Mn-free counterpart. An enhanced effect on magnetoelastic properties is achieved in Tb_0:12Ho_0:68Pr_0:2Fe_1:8Mn_0:1, which simultaneously possesses a low anisotropy and high magnetostriction performance, i.e. λ_s ~ 420 ppm, λ₁₁₁ ~ 970 ppm, and a large low-field λ_a ~ 390 ppm/2 kOe, being 30 % higher than that of Pr/Mn-free compound. Combining low-cost light rare earth Pr with the lower Tb content, Tb_0:12Ho_0:68Pr_0:2Fe_1:8Mn_0:1 may make it promising solution in magnetostrictive applications.