What's happening in the world of magnets?
The global drive for electrification, renewable energy, and advanced electronics has made rare-earth magnets (REEs), especially Neodymium and Samarium-Cobalt, crucial to modern supply chains. However, REEs face persistent supply, environmental, and geopolitical challenges, now exacerbated by rising demand and export limits. Fortunately, new magnet materials and design strategies are emerging that could lessen or even eliminate dependence on rare earths. Below are some of the most promising options, their trade-offs, and their near-term scalability.
Why the urgency
China now controls many of the world's rare earth mines and processing facilities, as well as much of the supply chain to make magnets. Changes in export controls or trade policy has had ripple effects across the world. Environmental and social costs associated with rare-earth mining (tailings, energy, and chemicals used) are significant as well.
With the deployment of electric vehicles, wind turbines, and other green technologies, demand for high-performance magnets should soar, posing even greater stress on the REE magnet supply chain.
Key alternative materials and technologies
Here are some of the top contenders for magnets that require far less rare earths, or none at all:
Iron Nitride (Fe-N)
Fe-N magnets (Iron-Nitride magnets) represent an attractive class of rare-earth-free permanent magnets based on abundantly available iron and nitrogen in nature. They've attracted serious consideration in recent years as a potential alternative for neodymium magnets.
What it is & why it's promising
Fe-N magnets are constructed from a metastable phase of Iron Nitride with the chemical formula of Fe16N2 per unit cell. The raw materials are also inexpensive and very plentiful. They have a very high saturation magnetization (apparently even higher than Neodymium in some lab tests). Containing no REE components, they cause a far lower environmental impact and are not geopolitically sensitive.
Challenges
While Fe-N magnets are very promising, some hurdles remain before they can be fully industrialized.
Producing Fe₁₆N₂ with high phase purity and uniformity is complex and not industrially scalable yet, though some companies like Niron Magnetics are aggressively pushing commercialization.
This phase is also metastable and tends to decompose above ~200 °C, limiting its maximum operating temperature.
Other concerns include low coercivity (difficulty of demagnetization), and limited mechanical robustness.
Tetrataenite (Fe-Ni “cosmic magnet”)
Tetrataenite, an alloy of Iron (Fe) and Nickel (Ni) with an ordered atomic structure, is another promising alternative. The material was originally found in iron meteorites, where it forms over millions of years as the meteorite slowly cools, giving the Iron and Nickel atoms enough time to order themselves into a particular crystalline structure, ultimately resulting in a material with magnetic properties approaching those of rare-earth magnets.
What it is & why it's promising
Tetrataenite has been synthesized in the laboratory by researchers in the University of Cambridge and the University of Sheffield in 2022 by adding small amounts of phosphorus to iron-nickel melts. This accelerates the crystallization process by many orders of magnitude, reducing the time taken to hours rather than millions of years. The base materials are abundant and relatively low cost. Since Fe-Ni alloys are easy to melt and shape, they can fit into existing metallurgical processes, unlike REEs which require complex powder metallurgy to form the finished product.
Challenges
The original process for synthesizing tetrataenite was complex and energy-intensive. While significant breakthroughs have simplified the process, scaling it up to industrial levels remains a major challenge.
Coercivity of the material is also low compared to Neo magnets, limiting its performance in high-load demagnetizing environments like electric motors and generators.
Manganese-Bismuth (MnBi)
MnBi refers to an intermetallic compound of Manganese (Mn) and Bismuth (Bi). It comes in several phases, but as a raw material for permanent magnets, the most interesting phase is the Low Temperature Phase (LTP) MnBi, which has the potential to replace rare-earth magnets in many applications.
What it is and why it's promising
MnBi crystals have a high magnetocrystalline anisotropy, because the spins of its component atoms prefer to align in one direction within the crystal. This results in high coercivity, or resistance to demagnetization. The coercivity, in fact, increases with temperature, unlike other magnetic substances. This unusual property makes it an excellent choice for high temperature environments. The magnetic field is stable under vibration and strong opposing magnetic flux, making MnBi magnets effective as base magnets for motors and generators as well.
Challenges
A relatively lower energy product compared to high-grade Neodymium magnets makes it unsuitable for some high-performance applications.
In addition, the synthesis process needs to be carefully controlled in order to achieve good magnetization properties. Scaling up production from lab samples to bulk industrial processes is difficult, and the associated cost of production might remove some of its advantage over REEs.
How the different magnetic materials stack up
At the cutting edge of industry
Several companies and research institutions are developing alternatives to rare-earth magnets.
Niron Magnetics (US) is leading the commercialization of Fe-Ni magnets with its “Clean Earth Magnet®” technology and plans a 1,500 ton/year pilot plant in Minnesota for EV, wind, and industrial applications, backed by major automakers and energy firms.
Institutions like Ames Laboratory, the University of Minnesota, and others in Japan, Germany, and China are working on advanced synthesis methods and enhancing coercivity through nanostructuring and alloying.
The University of Cambridge (UK) is looking to partner with industry to commercialize tetrataenite, while the Critical Materials Institute (US) and Korea Institute of Materials Science are pursuing MnBi-based magnets with commercial partners PowderMet and Novatech.
UK-based Materials Nexus is using AI to discover new magnetic materials, notably developing MagNex, which was designed, synthesized, and tested in just three months in collaboration with the Henry Royce Institute. Claimed to cut costs by 80% and CO₂ emissions by 70% compared to REE magnets, MagNex signals a new era in materials discovery.
Overall outlook
While new magnet technologies show great promise, several hurdles remain before they can reliably replace rare-earth magnets.
Scale and cost: Scaling from lab to industry demands consistent, defect-free production at low cost. This is the key focus for the industry right now.
Performance: New magnets must achieve sufficient remanence, coercivity, energy product, and corrosion resistance to be viable. Even if they fall short of REE magnets, many of them could still meet the needs of specific applications and reduce the reliance on REEs.
Processing: Techniques like nanostructuring, nitrogen insertion, and molecular beam epitaxy are complex and costly to scale, requiring government R&D support and industrial investment.
Environmental impact: Some alternatives may still face issues such as high energy use or hazardous by-products, potentially offsetting their advantages.
Still, momentum is building across research, startups, and industry. Even if those improvements are incremental or apply to just parts of a final design, they can have a huge influence in limiting the world's dependency on rare-earth magnets, making the next decade an exciting one for magnet innovation!