Structure and magnetostriction of Tb1−xNdx(Fe0.8Co0.2)1.93 alloys

The structure, magnetization and magnetostriction of Tb1−xNdx(Fe0.8Co0.2)1.93 (0 ≤ x ≤ 1.0) alloys have been investigated by means of X-ray diffraction, a vibrating sample magnetometer and a standard strain technique. X-ray diffraction (XRD) analysis shows that the alloys possess predominantly the cubic Laves phase with a MgCu2-type structure for x ≤ 0.6. The lattice parameter of the Laves phase increases with increasing Nd content and obeys the linear Vegardʹs law. The easy direction of magnetization (EMD) is observed toward <111> when 0 ≤ x ≤ 0.6, accompanied by a rhombohedral distortion with large spontaneous magnetostriction coefficients λ111. The saturation magnetization MS at room temperature (RT) decreases with increasing Nd content when 0 ≤ x ≤ 0.5, then increases with further increasing x for x ≥ 0.6. The linear anisotropic magnetostriction λa (= λ||– λ⊥) at RT decreases initially with increasing x when 0 ≤ x ≤ 0.4, then increases with a further increasing x and exhibits a peak in the range of 0.4 < x < 1.0.