< 1 1 0) Directional growth of polycrystalline magnetostrictive TbxDy1-xFey compounds by casting in a strong unidirectional gradient

Rods of highly magnetostrictive polycrystalline TbxDy1-xFey materials are e laborated by casting in a cylindrical mould with cooling imposed from the b ottom which leads to a fast vertical unidirectional growth. A [1 1 0] orien tation is obtained along the axis of the rods parallel to the growth direct ion. The magnetostrictive properties are remarkable along the rods axis com parable to those of [1 1 1] rods. The saturated magnetostriction measured i n a parallel magnetic field is lambda(parallel to) = 1124 x 10(-6) under 0 MPa and increases to 1760 x 10(-6) under a compressive stress of 25 MPa. Th e pseudolinear variation of the magnetostriction with the internal magnetic field Delta lambda(parallel to)/mu(0)Delta H-int reaches 640 x 10(-6)/0.04 T under 9.9 Mfa. The texture and the good magnetostrictive properties are reproducible. (C) 2000 Elsevier Science B.V. All rights reserved.