Improved magnetostriction in Fe83Ga17 alloy by tensile-stress annealing treatment

For optimizing the magnetostriction in Fe–Ga alloys, a novel tensile-stress heat-treatment method has been used for textured polycrystalline rods. Utilizing the consistency between the intrinsic magnetocrystalline anisotropy and the shape anisotropy in the textured structure, a large magnetostriction up to 200 ppm has been obtained in an alloy with composition Fe83Ga17 without application of pre-stress. Such samples also exhibit large pre-stress adjustable magnitude, about 90% for total magnetostriction. Due to the complete alignment of the magnetic moments, a magnetostriction contribution of the bcc (A2) phase can be ruled out and the magnetostrictive behavior of the Fe3Ga (DO3) phase has been investigated in detail.