Iron nitride compositions
All example composition may include a plurality of grains including an iron nitride phase. The plurality of grains may have an average wain size between about 10 nm and about 200 nm. An example technique may include treating a composition including a plurality of grains including au iron-based phase to adjust an average grain size of the plurality of grains to between about 20 nm and about 100 ma. The example technique may include nitriding the plurality of grains to form or grow an iron nitride phase.
1 . An alloy composition comprising:
a plurality of grains comprising an iron nitride phase,
wherein the alloy composition has a coercivity of at least about 2000 Oe,
wherein the average grain size is less than about 50 nm, and
wherein an average grain boundary size of the plurality of grains is between about 2 nm and about 5 nm, and
comprising a nonmagnetic element or compound configured to form domain wall pinning sites at the grain boundaries, wherein the nonmagnetic element or compound is selected from Cu, Zr, Ta, Ni, Ru, SiO 2 , Al 2 O 3 , or combinations thereof.
2 . The alloy composition of claim 1 , wherein the iron nitride phase comprises α″-Fe 16 N 2 .
3 . The alloy composition of claim 2 , comprising greater than about 50% by volume of the α″-Fe 16 N 2 phase.
4 . The alloy composition of claim 1 , wherein a majority of the plurality of grains have respective easy axes of magnetizing aligned in substantially the same direction.
5 . A bulk permanent magnetic material comprising the alloy composition of claim 1 .