Magnetic behaviors in melt spun Fe52−xMn23+xGa25 (x = 0–3) ribbons

Abstract

The effect of volume fraction of B2-type ferromagnetic (FM) phase on magnetic behavior of melt-spun Fe52−xMn23+xGa25 (x = 0, 1, 2, and 3) ribbons has been investigated. X-ray diffraction (XRD) results show that the volume fraction of the B2 phase is decreased, accompanied by the increased antiferromagnetic (AFM) fcc phase, with increasing x. The magnetization isotherms of these ribbons at different temperatures demonstrate that there exists a critical field HCR from AFM to FM state, and the HCR decreases and vanishes finally with increasing temperature. High exchange bias field (HEB) at 10 K through a cooling field at HCR from 300 K could be found and correlated to the volume fraction of B2-type FM phase. Both HCR and HEB are increased with decreasing the amount of B2-type FM phase. The HCR is increased from 20 kOe for x = 0 to 50 kOe for x = 3, and HEB is increased from 0.9 kOe for x = 0 to 2.5 kOe for x = 2. The latter phenomenon might be attributed to the change of exchange interactions at FM/AFM interfaces due to the change of proportion of FM and AFM phase at low temperature.