Magnetic Property Enhancement of Melt Spun YCo5 Ribbons by Fe and C Doping

Magnetic properties and microstructure of melt spun YCo
_5-x-y
Fe
_x
C
_y
(x = 0-0.3 and y = 0-0.3) ribbons are studied. Magnetic properties of YC
_o5
ribbons (
_i
H
_c
= 144 kA/m and (BH)
_max
= 16.8 kJ/m
³
are slightly improved to
_i
H
_c
= 160-224 kA/m and (BH)
_max
= 21.6-27.2 kJ/m
³
by Fe-doping, and are increased to
_i
H
_c
= 560-1128 kA/m and (BH)
_max
= 42.4-51.2 kJ/m
³
by C-doping, respectively. Most interestingly, the optimal (BH)
_max
of 72.8 kJ/m
³
with high
_i
H
_c
of 1200 kA/m achieved for Fe and C-co-doped YCo
_4.6
Fe
_0.3
C
_0.3
ribbons is the highest value in Y-Co alloy ribbons ever reported. The structural and thermo-magnetic analysis confirm that Fe and C enter the YCo
₅
(5:1) crystal structure and lead to the increase of Curie temperature. Besides, C-doping uniformly refines grain size and, therefore, improves the squareness of demagnetization curve and (BH)
_max
. The formation of YCo, Fe)
₅
C
_x
phase and the microstructure refinement are the main reasons to result in the enhancement of hard magnetic properties for the YCo
_4.4
Fe
_0.3
C
_0.3
ribbons. The presented results suggest that the YCo
₅
ribbons optimized by co-doping with Fe and C are promising candidate materials for making bonded magnets.