Enhanced magnetostriction of rolled (Fe81Ga19)99.93Tb0.07 thin sheet by synergy strategy of secondary recrystallization and trace Tb-doping

Abstract

Improving the magnetostriction of Fe-Ga thin sheets can significantly promote the magneto-mechanical conversion efficiency of Fe-Ga alloy devices at high-frequency magnetic fields. In this paper, the rolled (Fe81Ga19)99.93Tb0.07 thin sheet with excellent magnetostriction was developed by the synergy strategy of secondary recrystallization and trace Tb-doping. Centimeter-sized Goss grains were induced 0.27 mm-thick (Fe81Ga19)99.93Tb0.07 thin sheet by a composite inhibitor composed of nanometer-sized sulfides and Tb-rich precipitates. The remarkable reduction of the Tb-rich precipitates after quenching led to the dissolution of terbium in the matrix and result in the formation of the Tb-doping induced L60 nanoheterogeneities, which enhancing the lattice distortions in the matrix. The final saturation magnetostriction and the magnetostriction parallel to the rolling direction in (Fe81Ga19)99.93Tb0.07 thin sheets reached 378 ppm and 320 ppm, respectively, which is 30 % and 65 % greater than the undoped thin sheets. This Fe-Ga thin sheet with excellent magnetostriction, produced by a conventional rolling, annealing and quenching method, can greatly improve the conversion efficiency and apply to the next-generation magnetostrictive materials.