Structural, magnetic, and magnetostrictive properties of Tb1-xNdx(Fe0.9B0.1)2 alloys

The crystal structure, magnetization, and spontaneous magnetostriction of Tb_1-xNd_x(Fe_0.9B_0.1)₂ alloys have been investigated. X-ray diffraction (XRD) analysis shows that the alloys consist predominantly of the cubic Laves phase with a MgCu₂-type structure for x≤0.55. Increasing in lattice parameter and decreasing in Curie temperature with increasing x from 0 to 0.55 reveals an increment in the Nd content in the Laves phase. The (440) XRD line of the Laves phase splits doubly when x≤0.7 because of a large spontaneous magnetostriction along its <111> easy magnetization direction. The magnetostriction coefficient λ₁₁₁ decreases significantly with increasing x when 0≤x≤0.55. For x≥0.7, it is difficult to achieve saturation magnetization at room temperature due to increased amount of the Nd₂Fe₁₄B-type phase with large magnetocrystalline anisotropy.