Permanent magnets are used in the following major groups: acoustic transducers, motors and generators, magneto mechanical devices, and magnetic field and imaging systems. You will find permanent magnets in many products, such as televisions, telephones, computers, audio systems and automobiles.

The permanent magnet family consists, in general terms, of non-rare earth permanent magnets and rare earth magnets. The non-rare earth magnets include Alnico (Aluminum-Nickel-Cobalt) magnets and Ceramic (Strontium and Barium Ferrite) magnets. Rare earth magnets include Sm-Co (Samarium-Cobalt) magnets and Nd-Fe-B (Neodymium-Iron-Boron) magnets.

Although non-rare earth magnets are used in the majority of these applications due to their economic cost, rare earth permanent magnets have many distinguishing characteristics, such as a large Maximum Energy Product, (one performance index for permanent magnets). Dozens of magnetic materials which contain rare earth have been developed recently. Two major families of rare earth permanent magnets, Sm-Co magnets and Nd-Fe-B magnets, have been widely used in a variety of applications. Each family has its own advantages and disadvantages. 

How to Choose Permanent Magnet Materials

Each permanent magnet material discussed above has its own pros and cons. How to choose the right one for your particular application is a challenge to any user. A balance between cost and performance must be considered in selecting of permanent magnet material. In Reference Information section of this page, several reference books are listed. These books may be helpful to you in designing and selecting permanent magnet materials. Following is a Comparison Table to help you select a right permanent magnet material for your applications.

Permanent Magnet Material Comparison Table
Note: The data listed in the table are for reference only