Giant magnetostriction in Tb-doped Fe₈₃Ga₁₇ melt-spun ribbons

Giant magnetostriction is achieved in lightly Tb-doped Fe ₈₃Ga₁₇ melt-spun ribbons. The average perpendicular magnetostriction λ is -886 ppm along the melt-spun ribbon direction in the Fe_82.89Ga_16.88Tb_0.23 alloy and the calculated parallel magnetostriction λ is 1772 ppm. These values are more than four times as large as those found in binary Fe₈₃Ga ₁₇. The enhanced magnetostriction is attributed to a small amount of Tb entering solution in the A2 matrix phase during rapid solidification. The strong localized magnetocrystalline anisotropy of terbium is thought to cause the giant magnetostriction.