Effects of annealing and magnetic field on the structure and magnetic properties of Fe-Cr-Co alloy-doped Sm(Co0.9Cu0.1)5 ribbons

Sm(Co0.9Cu0.1)(5) ribbons doped by Fe-Cr-Co alloy were prepared by melt-spinning at 40 m/s and annealing at 450 degrees C for 15 min. The annealing and magnetic field have different effects on the structure and magnetic properties of the ribbons. The solute-partitioned structures consisting of Co-rich SmCo5- and (Sm, Cu, Fe, Cr)-rich CeCo5-type phases formed in each of the three ribbons. The as-spun ribbons show the SmCo5- and CeCo5-type phases in two distribution modes and high magnetic properties of H-c = 24.6 kOe, M-r = 45.4 emu/g and M-s = 61.5 emu/g. Annealing increases the content of SmCo5-type phase and enlarges the componential differences between the two Sm(Co, M)(5) phases, eventually leading to an increase in H-c and a decrease in M-r. MHT plays a vital role in promoting doping atoms to occupy the 2c sites, narrowing the differences in content and composition between the two Sm(Co, M)(5) phases, and forming a nearly equiaxed and uniform two-phase structure, which not only inhibits the negative effect of annealing on M-r but also increases H-c to 30.1 kOe and M-s to 63.0 emu/g.