Giant enhancement of magnetostriction in Pt doped FeGa ribbons

Abstract

FeGa alloys are among the most promising magnetostrictive materials. How to improve the magnetostriction of FeGa has been a long-term concern. In this work, trace amount of Pt doped FeGa-(Fe0.83Ga0.17)100–xPtx (x = 0, 0.2, 0.4, and 0.6) was fabricated using melt-spinning technique. The magnetostriction, crystal structure, and magnetocrystalline anisotropy of the ribbon samples were studied, revealing that the conforming between the crystal growth direction and the easy magnetization axis, and the enlarged lattice parameter both contribute to the enhancement of magnetostriction, which reached the maximum λ⊥ of −1369 ppm at the optimum composition x = 0.4. Finally, transmission electron microscopy was performed to show that nanoinclusions exist not only in Pt-doped but also in Pt-free samples, demonstrating that the nanoinclusions do not play the dominant role in magnetostriction improvement. This work may accelerate the design of highly magnetostrictive FeGa alloys and other magnetic functional materials, which are required of large magnetostriction.