Magnetostriction in antiferromagnetic Fe_1-xMn_x (0.30≤x≤0.55) alloys

Antiferromagnetic Fe_1-xMn_x (x=0.30, 0.35, 0.40, 0.50, 0.55 (atomic fraction)) alloys were prepared by induction melting method. A homogenization for 24 h at 1000°C was carried out on the samples, followed by furnace cooling to room temperature. The microstructures and magnetostrictive properties of Fe_1-xMn_x samples were investigated. It is found that when x≤0.40, Fe_1-xMn_x alloys consist of fcc γ and hcp ε phases with poor magnetostrictive property, and the volume proportion of ε phase decreases with the increase of Mn content. When x>0.40, the samples are single fcc γ phase and possess much better magnetostrictive performance. The magnetostriction of Fe_0.50Mn_0.50 sample reaches 8.73 × 10^-4 in 1.9 T magnetic field.