Nanocrystalline Soft Magnetic Fe-Si-B-P-Cu Alloys With High $B$ of 1.8–1.9T Contributable to Energy Saving

Melt-spun Fe
₈₅
Si
_1-2
B
_8-11
P
_1-4
Cu
₁
alloys have unusual hetro-amorphous structures which can transform to nanocrystalline structures composed of α-Fe grains with less than about 25 nm in size with crystallization. Especially, Fe
₈₅
Si
_1-2
B
_8-11
P
_1-4
Cu
₁
nanocrystalline soft magnetic alloys prepared by crystallizing an as-quenched nanohetero-amorphous phase including a large amount of extremely small α-Fe grains (less than 2-3 nm in size) exhibit high-B
₈₀₀
of 1.8-1.9 T (at 800 A/m) almost comparable to those of commercial oriented silicon steels and significantly higher than those of non-oriented silicon steels, along with extremely low core loss (W) which is 1/2-1/3 smaller than that of the highest-grade oriented silicon steel and about one-order smaller than those of non-oriented silicon steels at maximum flux density of 1.7 T. The nanocrystalline alloys with lower materials cost due to absence of rare-metals are expected to not only contribute to significant energy-saving and reduction of CO
₂
emission through reduction in W but also be useful to conserve the earth's resources and environment.