Samarium Cobalt Permanent Magnets: Composition, Types, and Unique Advantages

Mishma Industry (Shanghai) Co., Ltd. specializes in producing samarium cobalt permanent magnets, a high-performance magnetic material widely recognized for its exceptional temperature stability, corrosion resistance, and long-term reliability. Composed primarily of the rare-earth element samarium (Sm) and the transition metal cobalt (Co), SmCo magnets are among the most durable permanent magnets available today, making them ideal for critical applications in aerospace, defense, and advanced industrial equipment.

What Are Samarium Cobalt Permanent Magnets?

Samarium cobalt permanent magnets are part of the rare-earth magnet family, developed in the early 1970s as one of the first high-strength magnets to outperform traditional ferrite magnets. The unique combination of samarium and cobalt forms a crystalline structure that provides:

• High Magnetic Strength – While slightly lower in maximum energy product than neodymium magnets, SmCo magnets maintain strong performance in extreme environments.

• Exceptional Temperature Stability – Operating effectively in temperatures up to 250°C–350°C, far beyond the capability of most permanent magnets.

• Corrosion Resistance – Naturally resistant to oxidation and chemical degradation, eliminating the need for additional coatings in most environments.

These features make SmCo magnets especially valuable in applications where reliability under harsh conditions is essential.

Two Main Types of SmCo Magnets

1. SmCo₅ (Samarium Cobalt 1:5)

• Composition: 1 atom of samarium to 5 atoms of cobalt.

• Properties:

  • High magnetic strength with excellent corrosion resistance.

  • Easier to magnetize compared to Sm₂Co₁₇.

  • Slightly lower maximum operating temperature (~250°C) but still ideal for most high-performance needs.

• Applications: Precision instruments, medical devices, high-end sensors, and aerospace components.

2. Sm₂Co₁₇ (Samarium Cobalt 2:17)

• Composition: 2 atoms of samarium to 17 atoms of cobalt, with additional elements like iron, copper, and zirconium to enhance performance.

• Properties:

  • Higher maximum energy product and stronger coercivity than SmCo₅.

  • Exceptional high-temperature performance, with operating limits up to 350°C.

  • Superior resistance to demagnetization in demanding magnetic environments.

• Applications: High-temperature motors, wind turbine generators, military-grade sensors, and downhole drilling tools in the oil and gas industry.

Why Choose Samarium Cobalt Magnets from Mishma Industry?

• Material Purity: Sourced from high-quality rare-earth raw materials to ensure consistent performance.

• Precision Manufacturing: Advanced processing methods for tight dimensional tolerances.

• Application-Specific Design: Custom shapes, sizes, and magnetic orientations to meet unique industry needs.

• Reliability in Harsh Environments: Ideal for aerospace, automotive, marine, and industrial sectors requiring extreme durability.

Samarium cobalt permanent magnets offer an exceptional combination of strength, stability, and durability, making them indispensable in industries where performance under extreme temperatures and corrosive conditions is critical. Whether it’s the high coercivity of Sm₂Co₁₇ or the balanced performance of SmCo₅, Mishma Industry (Shanghai) Co., Ltd. delivers solutions tailored to meet the highest engineering demands worldwide.