Heavy rare earths: Enhancing heat resistance
While used in smaller quantities than their light rare earth counterparts, heavy rare earth elements – particularly dysprosium (Dy) and terbium (Tb) – play a critical role in improving the thermal stability and magnetic coercivity of NdFeB magnets. These properties enable the magnets to maintain their strength even at elevated temperatures, which is vital for applications like electric motors that operate in high-heat environments. Without these heavy rare earths, magnet performance would degrade under thermal stress, compromising the efficiency and durability of advanced systems.
Positive trial results show production of high-purity Tb and Dy metals will be possible at the Korean Metals Plant, with ASM targeting commercial production of the metals in 2025.
Dysprosium metal
Dysprosium is primarily used in high-performance permanent magnets, especially those found in electric vehicle motors, wind turbine generators, and industrial robotics. Its key role is to enhance magnetic coercivity, enabling magnets to retain their strength at high temperatures.
This makes dysprosium essential in applications where heat resistance and long-term performance are critical.
Terbium metal
Terbium is used in smaller amounts within NdFeB magnets to further improve thermal stability and magnetic strength under extreme conditions. Beyond magnets, terbium is also valued in solid-state devices, fluorescent lighting, and as a green phosphor in display technologies.
Its ability to modulate magnetic and optical properties makes it a versatile material in advanced electronics and clean energy systems.