Effects of rare-earth element substitution on magnetostrictive properties of polycrystalline Tb-Dy-Fe alloys

Magnetostrictive properties of (Tb_0.5Dy_0.5)_1-xRE_xFe_1.9 (x=0-0.05, RE=Y, Ce, Sm, Gd, Ho, Yb) polycrystalline compounds were studied. Each rare-earth element formed a RE-Fe₂ Laves compound with a different lattice spacing. Corresponding to this difference, (Tb_0.5Dy_0.5)_0.95RE_0.05Fe_1.9 alloys showed a variation in lattice spacing as a result of the substitution of rare-earth elements and the prestress dependence of magnetostriction changed noticeably. In the case of Y, Sm, and Gd substitution, which showed greater lattice spacing than that of the Tb_0.5Dy_0.5Fe_1.9 alloy, the prestress dependence and maximum magnetostriction decreased. On the other hand, in the case of Ce, Ho, and Yb substitution, which showed a decrease in lattice spacing, the conspicuous prestress dependence was the same as that of the Tb_0.5Dy_0.5Fe_1.9 alloy and the maximum magnetostriction was greater than that of the latter alloy.