SmCo magnets (Samarium Cobalt) have also a very strong magnetic field. They tend to resist demagnetization extremely well. Unlike Neodymium magnets, it is also very corrosion resistant. SmCo magnets can operate at higher temperatures up to 300°C and are widely used in applications in which higher operating temperature and higher corrosion and oxidation resistance are crucial. The temperature coefficient of remanence is usually less than ±0.05%. Two common compositions of SmCo magnets are SmCo5 and Sm 2Co17. They can be sintered and bonded. Generally, the cost of SmCo magnets is higher than NdFeB magnets. But NdFeB magnets are stronger than SmCo magnets.
An alloy compose of SmCo5/Sm2Co17 produce by powder metallurgical method
Extremely hard & brittle
High demagnetization resistance
Excellent anti-corrosion properties
More expensive than NdFeB magnets because of limited raw material supply