Reduced Critical Rare Earth High Temperature Magnet

A new permanent magnet composition, LaNdFe₁Co₂B, utilizes a reduced amount of critical rare earth elements while maintaining energy products as high as 37 MG-Oe (for a 25% substitution of Nd by La) , and potentially excellent performance at elevated temperatures. The composition offers significant cost savings (estimated at 40% for a 50% La substitution) and improved temperature stability compared to existing Nd₂Fe₁₄B and SmCo₅ magnets, making it ideal for critical applications such as electric vehicles and wind turbines. Notably, it contains none of the scarce, expensive and critical Dysprosium required for many Nd₂Fe₁₄B-based magnets.

Description

The newly developed permanent magnet, LaNdFe₂Co₂B, is designed to address the limitations of current high-performance magnets by reducing the dependency on critical and expensive rare earth elements. This innovative composition includes lanthanum (La), neodymium (Nd), iron (Fe), cobalt (Co), and boron (B), and exhibits exceptional Curie points well above 700K, compared to the 585K of commercial Nd₂Fe₁₄B magnets.

Key intrinsic features of LaNdFe₂Co₂B include a high magnetization of 1.5 Tesla at room temperature, an anisotropy field of 5.5 Tesla, and a significant energy product of up to 56 MG-Oe, with energy products of 37 MG-Oe and associated coercivities of 10 kOe achieved in laboratory tests. These properties ensure that the magnet performs reliably at high temperatures, making it suitable for applications that require high thermal stability.

The magnet’s formula allows for the fine-tuning of its properties by adjusting the ratios of La, Nd, and Co. This flexibility enables the creation of magnets with tailored characteristics for specific applications, ranging from electric motors and generators to medical devices and hard disk drives.

The production of LaNdFe₂Co₂B involves a process of melting and annealing the constituent elements under an inert atmosphere, resulting in a homogenous alloy with consistent magnetic properties. The freedom from dysprosium (Dy) and lower cobalt content make this magnet more cost-effective and less susceptible to supply chain disruptions.

Benefits

• High temperature stability: Curie point above 700K ensures performance at elevated temperatures.
• Cost-effective: Reduced usage of critical and expensive rare earth elements such as Nd and Co.
• High performance: Magnetization of 1.5 Tesla and an energy product of up to 56 MG-Oe, with 37 MG-Oe already achieved in the laboratory
• Customizable properties: Ability to fine-tune the composition for specific applications.
• Environmental sustainability: Less dependency on materials with significant geopolitical supply risks.

Applications and Industries

• Electric and hybrid vehicles: Enhanced performance and temperature stability for electric motor applications.
• Wind turbines: Reliable high-temperature operation for energy generation.
• Medical devices: High precision and stability for medical imaging and diagnostic equipment.
• Hard disk drives: Improved data storage capabilities with high coercivity and magnetization.
• Motors and generators: Efficient and durable performance in various industrial applications.

Contact

To learn more about this technology, email partnerships@ornl.gov or call 865-574-1051.