The magnetic hardening of the Sm2Fe14Ga3Cx was investigated by melt sp
inning. It was found that high coercivities can be achieved by direct
quenching at the optimum substrate velocity. The coercivities of 12.6-
15.0 kOe were obtained in SM2Fe14Ga3Cx ribbons with carbon contents x
from 1.0 to 2.5. The as-quenched Sm2Fe14Ga3C1.5 ribbons had a coercivi
ty exceeding 13 kOe within a large range of quench rates between 18 an
d 30 m/s. X-ray diffraction experiments indicate that the ribbons are
almost entirely comprised of the Tb2Zn17 phase. It is concluded that G
a not only stabilizes the hard magnetic phase but also is very effecti
ve in raising the coercivity in the SM2Fe14Ga3Cx melt-spun ribbons.