The hard magnetic properties, especially coercivity, of SmFe5, SmFe5C, SmFe5Ga, and SmFe5GaC alloys were examined. The SmFe5 and SmFe5C melt-spun ribbons did not show high coercivity even though the ribbons were annealed. The SmFe5Ga melt-spun ribbon exhibited a coercivity of 1.12 kOe, and the SmFe5GaC melt-spun ribbon showed a high coercivity of 12.2 kOe after annealing. Although both SmFe5Ga and SmFe5GaC melt-spun ribbons had the Sm(Fe,Ga)5 phase, the SmFe5GaC melt-spun ribbon exhibited a higher Curie temperature than the SmFe5Ga counterpart.
Saito et al. (Sun,) studied this question.