Rare earth element content in magnet

Rare earth elements are a group of 17 metal elements, including fifteen lanthanides on the periodic table, scandium and yttrium. They are an essential part of more than 200 products that are widely used, especially high-tech consumer products such as honeycombs. Telephones, computer hard drives, electric and hybrid cars, flat panel displays and TVs. Important defense applications include electronic displays, guidance systems, lasers, radars, and sonar systems. Although the amount of rare earth elements used in a product may not be an important part of the weight, value or volume of the product, rare earth elements are necessary for the operation of the equipment. For example, magnets made of rare earth elements usually account for only a small part of the total weight, but without them, the spindle motors and voice coils of desktop and notebook computers would not be possible.

What are the elements used to make permanent magnets?

Including samarium, neodymium, praseodymium, terbium and dysprosium.

What is the content of rare earth elements in magnets?

Magnets made of rare earth elements are what we call rare earth magnets. There are neodymium iron boron and samarium cobalt. The two types of magnets contain neodymium and samarium in rare earth elements. Ferrite is not a rare earth magnet, because it does not contain rare earth elements, and its magnetism is not that strong.

Neodymium iron boron magnets contain rare earth elements neodymium and dysprosium. Neodymium accounts for 29-32.5%, and dysprosium accounts for 0.6-1.2%. In many applications, the average content of rare earth metals is 31%.

Samarium cobalt magnets contain rare earth element samarium (Sm), which accounts for about 23-28%.

Related Knowledge Popularization: Heavy Rare Earth Elements and Light Rare Earth Elements

Light rare earth elements include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu) seven elements, also known as cerium group rare earth elements.

Heavy rare earth elements include gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu), and yttrium (Y) and scandium (Sc) Ten elements, also known as yttrium rare earth elements.

Note: The composition of the magnet can vary according to the application field. The neodymium iron boron metal working in a lower temperature range (such as for microphones) usually contains 31% neodymium and praseodymium elements, while in a relatively high temperature range ( For example, a part of the neodymium and praseodymium elements of the magnets working in the motor are usually replaced by dysprosium elements.