Tm-Substituted 2:17-Type Sm-Co Magnet
High-Temperature Low Temp. Coeff.
By stabilizing the 2:17H phase via Tm substitution, this magnet achieves an ultra-low remanence temperature coefficient of -0.008%/°C from 20 to 150°C while maintaining high room-temperature magnetic properties, resolving the trade-off between thermal stability and performance in traditional magnets.
Li, Yuqing
Materials Horizons 2026
Specifications
- Remanence temperature coefficient
- {'zh': '-0.008', 'en': '-0.008'} %/°C
- Maximum energy product at room temperature
- {'zh': '19.26', 'en': '19.26'} MGOe
- Remanence at room temperature
- {'zh': '9.25', 'en': '9.25'} kG
- Intrinsic coercivity at room temperature
- {'zh': '9.94', 'en': '9.94'} kOe
- Intrinsic coercivity after high-temperature processing
- {'zh': '25.03', 'en': '25.03'} kOe
Advantages
Ultra-low temperature coefficient
Tm stabilizes the 2:17H phase and suppresses phase decomposition, achieving a remanence temperature coefficient of -0.008%/°C from 20 to 150°C, significantly better than conventional magnets.
Maintains high room-temperature performance
Along with the low temperature coefficient, it achieves a room-temperature maximum energy product of 19.26 MGOe, remanence of 9.25 kG, and coercivity of 9.94 kOe, meeting application requirements.
Coercivity doubled after high-temperature processing
High-temperature processing refines the cellular structure and enhances Cu partitioning into cell walls, boosting coercivity from 9.94 kOe to 25.03 kOe, a 152% increase.
Applications
- Magnets for Precision Instruments：Provides a magnetic field nearly independent of temperature from 20 to 150°C, ensuring measurement accuracy and repeatability in precision instruments.
- Aerospace Permanent Magnets：Maintains field stability over wide temperature swings in aerospace environments, reducing the need for temperature compensation systems and saving weight.
- High-Temperature Motor Magnets：Retains high coercivity and low temperature coefficient at elevated temperatures, enabling stable motor output and improved demagnetization resistance.
- Magnets for Hypersonic Devices：Withstands extreme temperature fluctuations during hypersonic flight, keeping the magnetic field constant and ensuring device reliability.
- Magnets for Optoelectronic Devices：Provides a temperature-stable bias magnetic field for optoelectronic devices, stabilizing the operating point of lasers and optical modulators.