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

${\rm MnBi/Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$
bulk anisotropic hybrid magnets have been fabricated employing hot compaction of mechanically milled powders. The effects of
${\rm Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$
content on the magnetic properties, density and texture of the hybrid magnets were investigated. With increasing
${\rm Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$
content, the density of hybrid magnets decreases, their coercivity
$(H_{c})$
remains nearly constant, while the remanence
$(M_{r})$
increases drastically. The MnBi/40%
${\rm Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$
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%
${\rm Sm}_{2}{\rm Fe}_{17}{\rm N}_{\rm x}$
, which is 20% higher than that of single phase MnBi magnet [5.8 MGOe].