An introduction to terbium

Terbium demand and end-uses

Terbium’s diverse applications span electronics, energy, medicine, and advanced optical technologies, making it one of the most strategically significant rare earth elements. As demand for high-efficiency lighting, powerful magnets, and next-generation medical and renewable energy solutions continues to grow, terbium’s importance is expected to rise, securing its role as a critical material for future technological advancements.

One of the most significant applications of terbium is in phosphors for electronic displays and lighting. When excited, terbium compounds emit a brilliant green light, making them essential in various display and lighting technologies. Terbium oxide is extensively used in:

• Green phosphors for fluorescent lamps and television tubes.

• Colour TV tubes and flat-screen monitors, where its luminescent properties enhance image clarity.

• Trichromatic lighting technology, in which terbium "green" phosphors are combined with europium blue and red phosphors to produce energy-efficient white light.

These applications account for the largest share of global terbium consumption, as trichromatic lighting provides significantly higher light output per unit of electrical energy compared to incandescent lighting. With the increasing demand for energy-efficient lighting and advanced display technologies, terbium’s role in this sector remains critical.

Magnetic and magnetostrictive applications

Terbium’s magnetic properties have made it an essential component in high-performance magnets, which are crucial for various electronic devices, information technology, and data storage systems. These magnets offer exceptional stability, efficiency, and reliability, making them indispensable in modern technological applications.

One of the most significant applications of terbium is in Terfenol-D, an alloy known for its remarkable magnetostrictive properties. Magnetostriction refers to a material’s ability to expand or contract in response to a magnetic field, and Terfenol-D has the highest magnetostriction of any known alloy. This unique characteristic makes it invaluable in a range of precision mechanical and sensing applications.

Terfenol-D is widely used in actuators and sensors, where precise mechanical movement is required. In the naval sector, it plays a key role in sonar systems, significantly improving underwater navigation and detection capabilities. Its application in hydraulic valve drivers enhances efficiency in industrial processes, providing improved control and responsiveness.

The first commercial use of Terfenol-D was in the SoundBug device, which converts surfaces into speakers, demonstrating its ability to generate sound through magnetostrictive vibrations. Beyond this, the alloy is also used in other magnetomechanical devices, such as precision-controlled motors and transducers, which require highly sensitive and efficient response mechanisms.

A particularly valuable advantage of Terfenol-D is its ability to function effectively in extreme environments, including deep-sea applications. Its unique properties allow transducers to operate at greater depths for ocean exploration, maintaining high accuracy even at depths of 1,000 feet. This makes it a key material for next-generation sonar and underwater exploration technologies, ensuring minimal signal loss and enhanced performance in challenging conditions.

Energy applications

Terbium plays a crucial role in energy-related technologies, particularly in high-temperature fuel cells. It is used as a dopant in conjunction with zirconium dioxide (ZrO₂) to stabilise fuel cells operating at elevated temperatures, ensuring long-term efficiency and durability. This stabilisation is essential for the development of solid oxide fuel cells (SOFCs), which are considered a key advanced energy technology for clean and efficient power generation. As the demand for renewable energy solutions continues to rise, terbium's role in fuel cell innovation is expected to expand.

Beyond fuel cells, terbium is also being increasingly used in green and renewable energy applications, leveraging its magnetic and luminescent properties to enhance efficiency and performance. One of the most notable applications is in wind turbines, where terbium is used to produce high-performance magnets, helping to improve energy conversion efficiency and turbine reliability.

Terbium also contributes to energy-efficient lighting systems, particularly in LED and fluorescent lighting, where it enhances brightness and colour accuracy. This application aligns with the growing global emphasis on reducing energy consumption and transitioning to low-energy lighting solutions.

Another emerging use of terbium is in electric vehicle (EV) technologies, where it is incorporated into lightweight, high-performance materials that improve motor efficiency and battery technology. As the world shifts towards sustainable transport solutions, the need for terbium in EV components is expected to grow steadily.

Medical and biomedical applications of terbium

Terbium is attracting increasing interest in medicine and biomedical research due to its luminescence, magnetic properties, and biocompatibility. These unique characteristics make it valuable in diagnostics, targeted treatments, and regenerative medicine, driving advancements in medical imaging, drug delivery, and antimicrobial therapies. As research continues to uncover new applications for terbium-based technologies, its role in healthcare innovation is expected to expand, offering new and improved solutions for diagnostics, therapeutics, and regenerative medicine.

One of the most significant applications of terbium in healthcare is in the development of contrast agents for magnetic resonance imaging (MRI). Terbium-based compounds enhance image clarity and detail, allowing for more precise diagnostics and improved visualisation of tissues. This makes MRI scans more effective in detecting diseases, tumours, and internal abnormalities.

In biomedical research, terbium is used as a biochemical probe due to its similar behaviour to calcium. This allows scientists to study biological interactions at a molecular level, improving the understanding of cellular functions and disease mechanisms. Terbium’s ability to mimic calcium in biological systems makes it particularly useful for studying neurological and muscular processes.

Terbium is also playing a growing role in targeted drug delivery systems, where its compounds are used to improve the precision and effectiveness of medical treatments. By binding to specific molecules, terbium-based carriers help transport therapeutic agents directly to diseased cells, reducing side effects and enhancing treatment efficiency.

Another promising area of research involves terbium’s antimicrobial properties, which leverage reactive oxygen species (ROS) generation and surface charge interactions to combat bacterial infections. These properties are being explored for use in antibacterial coatings for medical devices and in therapeutic applications to reduce infections in wounds and implants.

In tissue engineering and wound healing, terbium has shown the ability to promote angiogenesis, cell proliferation, and growth factor stimulation, all of which are essential for tissue regeneration and repair. This makes terbium an emerging material in biomedical scaffolds, regenerative therapies, and wound care treatments aimed at accelerating healing processes.

Optical and specialised applications

Beyond its major industrial uses, terbium also plays a critical role in specialised optical and laser technologies, where its unique properties enhance precision, efficiency, and performance. These applications are particularly valuable in fields such as telecommunications, scientific research, and industrial optics.

One key use of terbium in optics is in optical isolators, which rely on terbium-doped garnets to prevent reflected light from travelling back along optical fibres. This enhances the efficiency of telecommunications networks by reducing signal loss and interference, ensuring higher data transmission reliability.

Terbium also contributes to laser technology through its use in sodium terbium borate compounds, which generate laser light for precision applications. These compounds are particularly important in high-precision industrial processes, scientific instruments, and medical lasers, where consistent and stable light output is essential.

In the field of speciality glasses, terbium is used to enhance optical and laser system performance, particularly in scientific and industrial settings. These advanced glass formulations improve light transmission, durability, and thermal stability, making them crucial for cutting-edge optical devices and high-powered laser systems.

Terbium is also making an impact in nanotechnology research, where it has been utilised in the creation of a lattice containing a single iron atom, examined using a synchrotron X-ray beam. This breakthrough marked the first successful attempt to characterise a single atom at sub-atomic levels, opening new possibilities for quantum computing, advanced materials, and atomic-scale imaging.

As research in optics, lasers, and nanotechnology continues to advance, terbium’s specialised applications are expected to expand, reinforcing its importance in next-generation scientific and technological innovations.

Terbium supply

Terbium, a member of the heavy rare earth elements (HREEs), is primarily extracted from monazite, bastnäsite, xenotime, and loparite. The leading producer of terbium is China, which dominates the global market, followed by the United States, Australia, and Brazil. Other countries with notable production include India, Russia, Vietnam, and Canada.

Terbium is typically obtained as a by-product of mining and processing other rare earth elements, particularly from deposits rich in neodymium, dysprosium, and yttrium. Since terbium is found in low concentrations, its extraction is dependent on the demand for these co-occurring elements. The processing of terbium involves solvent extraction and ion exchange techniques, which are necessary to separate it from other rare earths due to their similar chemical properties.

Environmental regulations, trade policies, and geopolitical factors also play a significant role in terbium’s supply chain, with China’s dominance in rare earth production posing potential risks to global supply stability. Efforts to diversify supply chains, particularly through rare earth projects in Australia, the United States, and Canada, are ongoing to reduce dependence on Chinese production and enhance supply security.