A magnetic powder core comprises a molded article of a mixture of a glassy alloy
powder and an insulating material. The glassy alloy comprises Fe and at least one
element selected from Al, P, C, Si, and B, and has a texture primarily composed
of an amorphous phase. The glassy alloy exhibits a temperature difference Tx,
which is represented by the equation Tx=Tx-Tg,
of at least 20 K in a supercooled liquid, wherein Tx indicates the crystallization
temperature and Tg indicates the glass transition temperature. The magnetic
core precursor is produced mixing the glassy alloy powder with the insulating material,
compacting the mixture to form a magnetic core precursor, and annealing the magnetic
core precursor at a temperature in the range between (Tg-170) K and
Tg K to relieve the internal stress of the magnetic core precursor.
The glassy alloy exhibits low coercive force and low core loss.
