An introduction to holmium

Holmium demand and end-uses

Holmium is a rare earth element with exceptional magnetic, optical, and neutron-absorbing properties, making it highly valuable across industrial, medical, and defence applications. While its demand is lower than that of neodymium or dysprosium, holmium plays a crucial role in high-performance magnets, nuclear safety, medical lasers, and advanced military technologies.

One of its primary uses is in high-performance magnets. When added to neodymium-iron-boron (NdFeB) magnets, holmium enhances their resistance to demagnetisation, particularly at high temperatures. This makes holmium-enhanced magnets vital for electric vehicle (EV) motors, wind turbines, and other high-temperature industrial applications where stability and durability are essential.

In the nuclear industry, holmium is used as a neutron absorber in nuclear control rods to regulate fission reactions in reactors and as a component in radiation shielding materials for enhanced nuclear safety. Its ability to stabilise nuclear reactions ensures safer and more efficient reactor operations, particularly in next-generation nuclear energy systems.

Holmium also has significant applications in medical and laser technology. Holmium-doped yttrium aluminium garnet (Ho:YAG) lasers are widely used in surgical procedures, particularly in urology for kidney stone removal, orthopaedic treatments, and ophthalmic surgery. These lasers offer high precision and minimal damage to surrounding tissues, making them ideal for minimally invasive procedures.

Holmium plays a critical role in military and scientific technologies, particularly in laser systems, stealth applications, aerospace alloys, and nuclear defence. Its unique optical, magnetic, and neutron-absorbing properties make it invaluable across multiple defence sectors.

One of holmium’s primary defence applications is in laser-based targeting and guidance systems. Holmium-doped solid-state lasers (Ho:YAG and Ho:YLF lasers) generate highly stable infrared beams, making them ideal for laser range-finding, target designation, and missile guidance. These lasers are also being developed for directed energy weapons (DEWs), which can disable enemy drones, missiles, and vehicles with precision-targeted high-intensity beams. Their energy efficiency and accuracy position them as key components in next-generation military laser weaponry.

Holmium is also used in stealth technology to reduce the radar cross-section (RCS) of military aircraft, ships, and vehicles. Its optical and electromagnetic absorption properties make it a key ingredient in radar-absorbing materials (RAMs), minimising detection by enemy radar systems.

In naval warfare, holmium is essential in acoustic stealth technology. It is used in magnetostrictive materials, which alter shape when exposed to a magnetic field, enabling their use in low-noise actuators and sonar suppression systems on submarines. These materials help reduce noise emissions, allowing submarines to operate undetected. Additionally, holmium is being explored for underwater acoustic stealth technologies, further enhancing submarine covert operation capabilities.

Holmium’s role extends to secure military communication and advanced surveillance systems. Specialised optical and infrared filters containing holmium enhance military satellite imaging and detection technologies, allowing them to operate efficiently in high-noise environments. Additionally, holmium-based laser communication systems enable secure, high-precision data transmission with a reduced risk of interception.

In aerospace and missile technology, holmium is alloyed with nickel and cobalt-based superalloys to improve thermal stability and oxidation resistance. These alloys are used in the production of jet engines, missile components, and hypersonic vehicles, ensuring they can withstand extreme operational conditions.

Holmium’s high neutron absorption makes it a vital material in radiation shielding for military-grade nuclear reactors and portable nuclear power sources. It is also used in protective coatings for personnel and equipment operating in high-radiation environments, such as nuclear-powered submarines and space missions.

With increasing military activity in space, holmium is gaining attention for its role in infrared sensors and laser-based tracking systems used to monitor and target satellites. Additionally, its high-strength alloys contribute to the development of space-based defence structures, ensuring durability and resistance to harsh space conditions.

Holmium is also one of the most magnetically powerful elements, making it useful in research and emerging technologies such as quantum computing and spintronics, where precise magnetic control is essential.

Although holmium’s applications are more specialised than those of other rare earth elements, its role in high-strength magnets, nuclear reactors, medical lasers, and defence technologies ensures continued demand. As advancements in clean energy, medical technology, and advanced computing progress, holmium will remain a critical material for cutting-edge industrial and scientific applications.

Holmium supply

Holmium, a heavy rare earth element (HREE), is primarily extracted as a byproduct of rare earth element (REE) mining, often alongside other middle and heavy REEs such as dysprosium, terbium, and gadolinium. Its main sources include monazite, bastnäsite, and xenotime, three of the most significant rare earth-bearing minerals. These deposits are primarily mined in China, the United States, Australia, Russia, India, Brazil, Vietnam, and Canada, linking holmium supply directly to global rare earth mining operations.

Other mineral sources containing holmium include loparite, allanite, aeschynite, parisite, synchysite, and eudialyte. However, holmium’s natural abundance is significantly lower compared to light rare earth elements (LREEs) like cerium or lanthanum, making its extraction more complex and dependent on the overall rare earth refining process.