In the US and Europe, there is an increasing recognition of the economic and national security dangers posed by depending too much on China for rare earth elements. A critical sector that may influence the direction of the worldwide climate economy is the industry for rare earth permanent magnets.
China holds significant control over the global supply chain for rare earth elements, accounting for more than 60% of the world’s production. This advantage has enabled it to dominate not just the extraction, but also the downstream manufacturing sectors, including rare earth magnets production.
China’s takeover of the magnet industry was facilitated by the absence of a rare earth supply chain in the Western hemisphere for many years. And is expected to extend its influence into downstream operations to capture a larger share of the commercial market.
In recent years, numerous manufacturers of rare earth permanent magnets have shifted their production facilities to China, largely attracted by the close access to raw materials. In 2016, Hitachi Metals, a top producer of magnets worldwide, initiated a joint venture with Zhong Ke San Huan, a leading Chinese magnets manufacturer. This step was described as crucial for achieving worldwide expansion in their magnets business.
What are Rare Earth Magnets?
“Permanent magnets are named as such due to their ability to retain their magnetic characteristics even when subjected to an external magnetic field. In other words, these magnets possess constant magnetic fields. There are four primary categories of permanent magnets: 2 types are made without rare earth elements, and 2 types incorporate rare earths in their composition,” explains Girish Linganna, Bengaluru based Aerospace & Defence Analyst.
What are Rare Earth Materials?
Rare earth materials, including the lanthanide series from lanthanum to lutetium, plus scandium and yttrium, are found in the periodic table’s f-block and Group 3. Rare Earth materials, often classified into 17 types, are essential elements used in various high-tech applications.
According to Linganna, “These can be divided into two main categories based on their atomic weights: Light rare earth elements (LREEs); and Heavy rare earth elements (HREEs). LREEs include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm) and europium (Eu). Among these, promethium is primarily synthetic and rare in nature. HREEs consist of gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). Additionally, yttrium (Y), though not part of the lanthanide series, is commonly included in HREEs due to its similar chemical properties and is often found in the same mineral deposits.”
The distinction between light and heavy rare earths is significant as it impacts their abundance, extraction difficulty and the range of applications they are suited for.
Samarium-Cobalt (SmCo) Magnet
The initial development of rare earth magnets occurred in the 1960s in the US, utilizing the rare earth element, samarium, combined with the metallic element cobalt. This combination, known as the Samarium-Cobalt (SmCo) Magnet, significantly outperformed earlier versions of permanent magnets in terms of strength. It also sparked a renewed interest in magnet research.
Neodymium-Iron-Boron (NdFeB) Magnet
In the 1980s, scientists in Japan and the US independently created a more cost-effective and more powerful rare earth magnet, known as the Neodymium-Iron-Boron (NdFeB) Magnet. Currently, the NdFeB Magnet dominates the global production of permanent magnets made from rare earth materials.
Rare earth magnets exhibit strong remanence and coercivity and their magnetic energy levels significantly surpass those of other types of magnets. However, the Curie temperature, which is the point at which they lose their magnetism, is notably lower for neodymium magnets compared to that of other magnets.
Defence Applications:
Samarium-Cobalt Magnets
These are magnets with high coercivity, resistance to demagnetization and thermal stability and are greatly valued by the military. SmCo, in particular, maintains its magnetic potency even at high temperatures, making it perfectly suited for military applications, such as precision-guided missiles, smart bombs and aircraft technologies.
Samarium cobalt’s effectiveness across a wide temperature range, from -55°C to 125°C, makes it essential for defence purposes, particularly in the electronic warfare systems of fighter jets. These systems need to function flawlessly under severe conditions, including at altitudes of up to 70,000 feet, where samarium cobalt’s reliability is critical. Samarium-cobalt permanent magnets are also used to direct the electron beam in radar magnetron tubes. These tubes are important for managing air traffic and surveillance from the ground, as well as for radar used in searching and controlling weapons fire.
Neodymium Iron Boron Magnets
These are recognized as the strongest permanent magnets available, making them highly sought-after for defence purposes. Their remarkable power, combined with their light weight, makes them ideal for such applications.
Neodymium iron boron magnets, notable for their potent strength and compactness, serve as a vital underpinning for specialized defence tools. This encompasses cutting-edge military weaponry, as well as critical computer software and disk drives essential to conducting military research and operations.
NdFeB Magnets are recognized as the strongest permanent magnets globally and are crucial for numerous military weapons systems. Their exceptional power enables the design of defence weapon systems that are smaller and lighter, thanks to the use of these magnets.
Use of Rare Earth Magnets
Magnetic Storage Media for Computers; Power Generation in Wind Turbines; Audio Equipment, such as Speakers and Headphones; Fishing Reel Brakes; Cordless Drills with Permanent Magnet Motors; High-Performance AC Servo Motors; Traction Motors in Hybrid or Electric Vehicles; Handheld Flashlights with Shake-to-Generate Electricity Feature; Linear Motors Deployed in Maglev Trains; Electric Bearings; Toys Utilizing NdFeB Magnets; Electric Guitar Pickups; and Health Care.
According to Linganna, “Neodymium magnets are widely used in the healthcare industry, particularly in medical devices, such as magnetic resonance imaging (MRI) machines. These magnets play a vital role in diagnosing and treating various conditions, such as chronic pain syndrome, arthritis, wound healing, insomnia, headaches and other illnesses. This is due to their capability to produce a stable magnetic field (a consistent and unchanging magnetic force over time). In recent years, there has been a noticeable rise in their usage. These magnets are often referred to as “magic magnets” because they are believed to have healing properties.”
Adding, “NASA utilizes neodymium magnets to preserve the muscle tone of astronauts while they are in space. Studies have indicated that a static magnetic field has the potential to promote bone formation by stimulating the differentiation or activation of osteoblasts. A static magnetic field has been found to encourage the development and activation of bone-building cells, called osteoblasts, which can help in the formation of new bone tissue.”
According to him, “Repetitive transcranial magnetic stimulation (rTMS) is an approved and effective treatment for major depression. A modified version, called synchronized TMS (sTMS), has also been explored for the same purpose. In a 2014 study, it was found that the occurrence of major depression decreased by 48% in patients treated with sTMS, compared to a 19% decrease in the control group. This difference was statistically significant. Neodymium magnets are used in TMS to generate magnetic fields. Unlike electroconvulsive therapy, TMS does not require anaesthesia. Another study conducted in 2015 also demonstrated the effectiveness of sTMS in treating major depression.”