Elements of Desire: What Are Rare Earth Magnets and Why Does Everyone Want Them?
- Alisa Peters
- 5 minutes ago
- 4 min read
If you've followed this series, you've noticed that the word "neodymium" keeps showing up like an uninvited party guest. It showed up in our magneto case study where we upgraded those magnets from Alnico to Neodymium. It showed up in the hydrogen decrepitation post, where NdFeB magnets are the ones that quietly crumble into powder when hydrogen gets in. It is, apparently, everywhere in the magnet world, and I have been nodding along like I understood it this whole time. I did not. So let's actually figure out what rare earth magnets are, why they're so powerful, and why entire governments are scrambling to control them.
For a complete background on who I am and why this post exists, head over to the Introduction to Alisa Learns about Magnets. To monitor production volumes and supply chain maturity across domestic manufacturers as you read, open up our interactive U.S. Rare Earth Magnet Supply Chain Dashboard.
💡 TLDR: What we're covering
What makes a magnet "rare earth"
Why neodymium (NdFeB) magnets are so outrageously strong
Where they show up (spoiler alert: everywhere)
Why there's a geopolitical scramble to control them
How to track production capacity via our U.S. Rare Earth Magnet Supply Chain Dashboard
Are Rare Earth Elements Actually Rare?
Sort of, but not in the way the name implies. Rare earth elements (REEs) are a group of 17 metallic elements—the 15 lanthanides on the periodic table, plus scandium and yttrium. They're not especially scarce in the earth's crust. Cerium, for example, is more abundant than copper. The rare part comes from the fact that they almost never appear in deposits concentrated enough to mine economically. They're scattered through rock in trace quantities, intermingled with other minerals and often sitting alongside mildly radioactive thorium and uranium. Extracting and refining them is technically demanding, environmentally intensive, and expensive. That's what makes them practically rare.
Neodymium and Samarium Cobalt Magnets (NdFeB and SmCo)
Most rare earth magnets you'll encounter fall into one of two categories:
Neodymium Iron Boron (NdFeB): The strongest type of permanent magnet that exists. A neodymium magnet the size of a golf ball can lift hundreds of pounds. They're the gold standard for EV motors, wind turbines, hard drives, and consumer electronics. The tradeoff is temperature: many grades of NdFeB begin losing their magnetism above 80°C, which matters in high-heat environments.
Samarium Cobalt (SmCo): Slightly less powerful than NdFeB, but it shrugs at heat. SmCo magnets can operate up to 300-350°C without degrading, which is exactly why they're the magnet of choice in aerospace, motorsports (like the drag racing magneto we covered earlier), and high-temperature industrial applications where NdFeB would give up and go home.
What Makes Rare Earth Magnets So Strong?
Bohr models for Neodymium and Samarium. Image credit: Ahazard.sciencewriter, CC BY-SA 4.0, via Wikimedia Commons
The mechanics come down to quantum structure. Lanthanide elements possess unfilled 4f electron subshells containing unpaired electrons that produce a large net magnetic moment. When alloyed into a rigid crystal lattice with transition metals like Iron or Cobalt, these 4f orbital interactions create powerful magnetocrystalline anisotropy: a structural preference for atomic magnetic moments to align along a single axis and resist flipping.
This atomic alignment gives NdFeB roughly 10 times the magnetic energy density of standard ferrite magnets, allowing engineers to squeeze maximum magnetic torque into minimal envelope space.
Where Rare Earth Magnets Are Used
The short answer: everywhere.
Electric vehicles: A single EV traction motor can contain a kilogram or more of rare earth magnets. Every electric vehicle on the road is a rare earth consumer.
Wind turbines: Direct-drive offshore wind turbines can use 600+ kilograms of rare earth magnets per unit. A single wind farm represents a significant draw on global supply.
Consumer electronics: Your smartphone has around a dozen rare earth magnets: in the speakers, camera optical image stabilization, the haptic motor, and the microphone.
Defense: Guided munitions, radar systems, sonar arrays, and electric propulsion in submarines all depend on rare earth magnets.
Medical devices: MRI machines rely on rare earths throughout their subsystems, and as we discussed in the magnetic dipole post, magnetic precision in medical imaging is non-negotiable.
Global Supply Chains and Geopolitics
According to reports from the U.S. Geological Survey (USGS), China controls roughly 60% of global rare earth mining and approximately 85% of the world's rare earth processing capacity. That's not a modest dependency, it's a near-monopoly on a material that's simultaneously embedded in clean energy infrastructure, national defense, and consumer electronics. According to live metrics tracked on our U.S. Rare Earth Magnet Supply Chain Dashboard, domestic alternative capacity is expanding across midstream alloy synthesis and downstream magnet sintering, though processing reliance remains high.
The US, EU, and Australia have all designated rare earths as "critical minerals" and are funding alternative supply chains, domestic mining projects, and recycling programs.
That last one connects back to something we covered in the hydrogen decrepitation post. One of the most promising recycling methods involves intentionally using hydrogen to break old NdFeB magnets down into recoverable powder. What looks like a failure mode in the field turns out to be a useful manufacturing and recovery tool, and potentially a meaningful piece of making the rare earth supply chain more sustainable.
Whether supply chains diversify fast enough to meet the demand from EVs and wind energy over the next decade is an open question. What's not open is that rare earth magnets are load-bearing infrastructure for the clean energy transition.
If your project depends on rare earth magnets, connect with an engineering team that knows the materials, tradeoffs, and supply dynamics: Contact QT Magnetic Solutions. (I'll be memorizing the lanthanide row of the periodic table. Row 6 is harder than it looks.)