Magnetostriction of growth textured Tb–Zn alloys

The magnetostrictive performance of aligned microstructural composites of Tb–Zn alloys were experimentally tested at 77 K under compressive loads ranging from approximately 0–50 MPa and applied magnetic field up to 2000 Oe. Tb-8a/oZn, Tb-42a/oZn and the eutectic composition of Tb-27.8a/oZn were all directionally solidified to prepare aligned, textured microstructures. The eutectic sample grew with lamellar plates with the magnetically hard axes for each phase parallel with the rod axis and exhibited a strain of less than 100 ppm. The Tb-42a/oZn alloy solidified with TbZn dendrites in the magnetically hard [1 1 1] direction and exhibited a strain of 375 ppm. The Tb-8a/oZn alloy solidified pure Tb dendrites in the magnetically easy direction, the b-axis, yet it only displayed a 350-ppm magnetostriction at a maximum field of 2000 Oe due to the high anisotropy of the Tb dendrites.