Specification :

Rare Earth Magnet
Neodymium Iron Boron (NdFeB) and Samarium Cobalt (SmCo) are called Rare Earth because Neodymium and Samarium are found in the rare earth elements on the periodic table. Both Neodymium and Samarium Cobalt alloys are powdered metals which are compacted in the presence of a magnetic field and are then sintered.
Neodymium (Rare Earth)
Neodymium, or Neo, is made up of Neodymium Iron and Boron and is moderate in price. With poor corrosion resistance this alloy is usually plated or coated (Examples: Nickel Plated, Epoxy Coated, Parylene Coated). Neodymium is offered in a range of operating temperatures depending on your application (80°C to 200°C). Premium Neodymium Alloys capable of operating above 120°C can become quite expensive. This permanent magnet material has many intellectual property rights associated with it and there are a limited number of licensed manufacturers in the world. Many infringing manufacturers from the Pacific-rim dump sub par material into the Western markets. This magnet material is extremely powerful and it has allowed for the miniaturization of many products from HDD (Hard Disc Drives) and motors to novelties and audio devices. Neodymium permanent magnets usually offer the best value when comparing price and performance.
Samarium Cobalt (Rare Earth)
Samarium Cobalt is made up of largely Samarium and Cobalt and it is the most expensive magnet material to manufacture and to fabricate. Most of the cost is due to the high Cobalt content and the brittle nature of the alloy. This permanent magnet material offers high resistance to corrosion and it can withstand high operating temperatures, up to 350°C. This material is used extensively in the aerospace market or in areas of industry where performance is the priority concern and cost is secondary. Samarium Cobalt is the second most powerful magnet material and it exhibits excellent resistance to demagnetization