Phase structures and magnetostrictive properties of Fe_72.5Ga_27.5 alloy

The phase structures and magnetic properties of Fe_72.5Ga_27.5 alloy prepared by different processes were studied. The results show that only D0₃ phase remains in Fe_72.5Ga_27.5 alloy under as-cast, directionally solidified and melt-spinned or quenched states, while L1₂ phase appears under furnace cooling condition. The saturation magnetization of the alloy reaches 140 A·m²/kg after furnace cooling, and slightly reduces after quenching, directional solidification and melt-spinning. The saturation field of the melt-spinned alloy is 160 kA/m, lower than those of the samples prepared by other mentioned methods. The saturation magnetostriction of Fe_72.5Ga_27.5 alloy is -59 × 10^-6 under furnace cooling condition, but 53 × 10^-6 for as-cast and directionally solidified, and 114 × 10^-6 for the sample quenched from 1000°C. The different values of the saturation magnetostriction of the alloy are attributed to various phase structures.