Enhanced magnetization and energy product in isotropic nanocrystalline Mn55Al45 alloys with boron doping

A high magnetization and large energy product (BH)max in the isotropic nanocrystalline τ phase Mn54.45Al44.55B1 alloy were reported. The formation activation energy and the temperature of the τ phase transformation in the MnAl-based alloys were reduced with the addition of boron element. In addition, a high magnetization of ∼127 emu/g was achieved. The addition of boron element can obviously enhance the coercivity of the MnAl-based alloys. Moreover, a high (BH)max of ∼5.5 MGOe was reached in the Mn54.45Al44.55B1 alloy. Therefore, this work can open a direction to realize the high performance in the MnAl-based rare-earth-free permanent magnets.