Effects of transition metals (V, Cr, Mn, Fe and Ni) doping on magnetic properties of Co-based amorphous alloys

Amorphous alloys exhibit numerous interesting and abundant magnetic properties due to their disordered structural traits and have been extensively studied by researchers. In this work, the effects of a small amount of transition metals doping on the magnetic properties of Co_80-xM_xB₂₀ (x = 0, 2, 4, 6, 8, 10; M = V, Cr, Mn, Fe, Ni) amorphous alloys were systematically investigated by utilizing first-principles molecular dynamics. The trend of the magnetic moment change in the simulated calculation conforms well to the experimental results. The doping of V atoms leads to the fastest rate of decrease in the magnetic moment of the surrounding Co atoms, and there is only an antiferromagnetic interaction between the V and Co atoms. When doped with Cr and Mn atoms, there is mutual competition between ferromagnetic and antiferromagnetic coupling in the amorphous alloy, Cr reduces the magnetic moment of the surrounding Co atoms, while the change in the magnetic moment of the Co atoms around Mn is small. The doping of Fe and Ni causes an increase in the magnetic moment of the surrounding Co atoms. The reason may be due to the charge transfer between atoms. The doping of Fe and Ni has a small effect on the average magnetic moment of the Co atoms in the amorphous alloy. The results provide necessary theoretical support for the development of the Co-based amorphous alloys with excellent magnetic characteristics.