Samarium Cobalt alloy is composed of Samarium, Cobalt, and minor amount of Fe, and Cu. By varying the percentage of its composition and altering the sintering process and heat treatment cycles, the 2 grades, SmCo5 and Sm2Co17 are produced.
SmCo has high induction and high resistance to demagnetization with outstanding thermal stability. SmCo would be your first choice of magnetic material if high temperature application is a concern.
In addition, SmCo has high resistance to oxidation and corrosion, and surface treatment is not required in general.