Magnetic properties and thermal stability of MnBi/SmFeN hybrid bonded magnets

Abstract

Anisotropic MnBi/SmFeN (MnBi = 0, 20, 40, 60, 80, and 100 wt. %) hybrid bonded magnets were prepared using MnBi powders and commercial SmFeN powders. With the increase in MnBi content from 0 to 100 wt. %, the density of the hybrid magnets improves linearly from 4.27 g/cm3 to 6.3 g/cm3, while the coercivity of the hybrid magnets does not change much at 293 K. For the pure MnBi magnet, the coercivity is increased from 10.76 kOe at 293 K to 16.5 kOe at 373 K. For the hybrid magnet with 40 wt. % MnBi, the coercivity is increased by 19% compared to pure SmFeN magnet at 373 K. In the temperature range of 293 K-373 K, the coercivity temperature coefficient of the hybrid magnets changes gradually from -0.42%/K for the pure SmFeN magnet to -0.11%/K for the magnet with 80 wt. % MnBi, and becomes 0.67%/K for the pure MnBi magnet. © 2014 AIP Publishing LLC.