Rare_Earth Magnets:

Neodymium Iron Boron and Samarium Cobalt are collectively known as Rare Earth magnets because they are both composed of materials from the Rare Earth group of elements.

Neodymium Iron Boron (general composition Nd2Fe14B, often abbreviated to NdFeB) is the most recent commercial addition to the family of modern magnet. NdFeB magnet is the strongest permanent magnet nowadays, and it has the merits of high remanence, high coercive force, high energy product and high price/performance ratio. Meanwhile, it could be easily processed into various shapes and specifications. Now, it is widely applied in the fields of aviation, automobile, electronics, communications equipment, meters and so on.

Samarium Cobalt is manufactured in two compositions: Sm1Co5 and Sm2Co17, often referred to as the SmCo1:5 or SmCo 2:17 types. 2:17 types, with higher Hci values, offer greater inherent stability than the 1:5 types. SmCo magnets withstand higher temperatures than do NdFeB magnets. It can operate at temperatures up to 350 degrees Centigrade. Sm2Co17 materials exhibit superior temperature characteristics as compared to the Sm1Co5 types. SmCo materials are very brittle, and great care must be taken in machining them. And the corrosion resistance of SmCo is considered “good”, so they are widely used in motors, meter, engine, sensor, radar and other high-tech fields.