The effects of CNTs and/or Si additions on the structure and magnetic properties of SmCo7-based alloys

► We studied the effects of CNTs and/or Si additions on the SmCo7-based alloys. ► Si can stabilize the TbCu7-type structure while CNTs induce Sm2Co17-type phase. ► Cooling rate plays a more important role in forming TbCu7-type phase than dopants. ► Simultaneous addition of CNTs and Si can enhance the coercivity dramatically. ► Reversal magnetization mechanism of SmCo7-based ribbons with dopants was discussed.