Rare Earth Magnets: from Samarium-Cobalt to Neodymium Iron Boron
Dive into the fascinating world of rare earth magnets, focusing on Samarium-Cobalt and Neodymium magnets, with Tengye Magnetic. Learn how these exceptional magnets evolved over time, their unique properties, and how they can propel your products to new heights. Get in touch with us for customized magnetic solutions.
Understanding Rare Earth Magnets
Rare earth magnets, as their name suggests, are strong permanent magnets made from alloys of rare earth elements. Boasting an impressive magnetic field strength, they exceed their hard ferrite or AlNiCo counterparts in performance, making them the preferred choice for modern technological applications.


The Evolution of Rare Earth Magnets
The history of rare earth magnets traces back to the 1960s. Their development can be categorized into three main generations, each signifying a significant leap in technology and application.
First Generation: Samarium-Cobalt Magnets
The first generation of rare earth magnets, the Samarium-Cobalt 5 (SmCo5) magnets, emerged in the 1960s. Created from an alloy of samarium and cobalt in a 1:5 ratio, these magnets provided impressive magnetic properties and an excellent resistance to demagnetization. Although they can operate at higher temperatures, reaching up to 250-300°C, their magnetic strength is lower compared to the later developed Sm2Co17 magnets.
Second Generation: Sm2Co17 Magnets
In the mid-1970s, the second generation of Samarium-Cobalt magnets, Sm2Co17, was developed. This version introduced iron into the alloy, resulting in a composition of two parts samarium, 13-17 parts cobalt, and small amounts of iron and copper. The addition of iron increased the magnet’s maximum energy product, making Sm2Co17 magnets stronger than their SmCo5 counterparts. Additionally, they have a higher Curie temperature, offering better temperature stability and making them suitable for even higher temperature applications.
Third Generation: NdFeB Magnets
The third and most recent generation of rare earth magnets, Neodymium-Iron-Boron (NdFeB) magnets, came into existence in the 1980s. These magnets have the highest maximum energy product of any type of magnet, making them extremely powerful for their size. However, their resistance to demagnetization at high temperatures is lower than that of Samarium-Cobalt magnets, limiting their use in high-temperature applications.
Rare Earth Magnets: A Catalyst for Sustainable Technology
Apart from their impressive properties, rare earth magnets are also instrumental in driving sustainable technology. They play a crucial role in electric vehicles and wind turbines, helping the world transition to cleaner, renewable energy sources.
Tengye Magnetic: Your Partner in Magnetic Solutions
In summary, each generation of rare earth magnets has its unique strengths and trade-offs. SmCo5 magnets offer excellent temperature resistance and magnetic properties. Sm2Co17 magnets enhance these properties with higher magnetic strength and better temperature stability. NdFeB magnets provide unparalleled magnetic power for their size, but their application is limited in high-temperature environments.
At Tengye Magnetic, we understand these variations and work closely with our customers to provide the best magnetic solution for their specific needs. Whether it’s the high-temperature resistance of Samarium-Cobalt magnets or the remarkable strength of Neodymium magnets, we have the expertise to guide you. Reach out to us today to discover how our top-quality rare earth magnets can improve your business operations.