Anisotropic ${\rm MnBi/Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$ Hybrid Magnets Fabricated by Hot Compaction

MnBi/Sm₂Fe₁₇N_x bulk anisotropic hybrid magnets have been fabricated employing hot compaction of mechanically milled powders. The effects of Sm₂Fe₁₇N_x content on the magnetic properties, density and texture of the hybrid magnets were investigated. With increasing Sm₂Fe₁₇N_x content, the density of hybrid magnets decreases, their coercivity (H_c) remains nearly constant, while the remanence (M_r) increases drastically. The MnBi/40% Sm₂Fe₁₇N_x magnet displays an H_c value of 5.7 kOe with M_r of 69 emu/g; these values for pure MnBi magnet are 6.5 kOe and 45 emu/g. An energy product [(BH)_max] of 7 MGOe was obtained in the hybrid magnet with 40% Sm₂Fe₁₇N_x, which is 20% higher than that of single phase MnBi magnet [5.8 MGOe].