Directional growth of polycrystalline magnetostrictive TbxDy1−xFey compounds by casting in a strong unidirectional gradient

Abstract Rods of highly magnetostrictive polycrystalline Tb x Dy 1− x Fe y materials are elaborated by casting in a cylindrical mould with cooling imposed from the bottom which leads to a fast vertical unidirectional growth. A 〈1 1 0〉 orientation is obtained along the axis of the rods parallel to the growth direction. The magnetostrictive properties are remarkable along the rods axis comparable to those of 〈1 1 1〉 rods. The saturated magnetostriction measured in a parallel magnetic field is λ ‖ =1124×10 −6 under 0 MPa and increases to 1760×10 −6 under a compressive stress of 25 MPa. The pseudolinear variation of the magnetostriction with the internal magnetic field Δ λ ‖ /μ 0 Δ H int reaches 640×10 −6 /0.04 T under 9.9 MPa. The texture and the good magnetostrictive properties are reproducible.