12 Things You Didn’t Know About Rare Earth Metals
1 They’re Not That Rare. Most of the rare earth metals really aren’t that rare. Cerium (Ce) is the most abundant rare earth metal, followed by Lanthanum (La), and then Neodymium (Nd). Cerium, Lanthanum and Neodymium are all more abundant than Lead (Pb).
2 It’s actually PrNd, not Nd. Praseodymium is right next to Neodymium on the periodic table. All of the Rare Earth Elements are chemically very similar, so they are difficult to separate. But Pr and Nd are so similar that for magnets, they are practically identical. So manufacturers of neodymium magnets don’t bother to separate them. Most neodymium in magnets actually is 25-35% praseodymium, so only about 65-75% of the “neodymium” is really neodymium.
3 Neodymium magnets are comprised of approximately 65% iron (Fe). That’s right. Neodymium magnets are ferromagnetic as with most permanent magnets. The Neodymium, Iron and Boron work together synergistically to make the strongest room-temperature permanent magnet in the world.
4 When researchers discovered the NdFeB system, they experimented with Boron (“B” is for Boron) thinking it would make the composition into a soft magnet. The Boron actually ended up accentuating the permanent ferromagnetic properties this composition is known for today.
5 High-temperature Neodymium magnets need to have Heavy Rare Earths (HRE’s) added to maintain their properties at high temperatures, but technological advances are reducing the need for HRE’s. A few magnet manufacturers –including MPCO Magnet Solutions- are using a technology called Grain Boundary Diffusion to deliver HRE’s straight to the grain boundaries where they are most useful.
6 Dysprosium (Dy) and Terbium (Tb) are Heavy Rare Earth (HRE) metals used to enhance the high-temperature performance of Neodymium magnets. Dy and Tb are both rare and expensive, and they are found in very few mines outside China. As the demand for Rare Earth Magnets has increased, leading magnet manufacturers have found ways to achieve the same high-temperature performance with less HRE’s.
7 Rare earth metals are used in anti-counterfeiting industry. Notably, the fluorescence of compounds of Dysprosium, Europium and Terbium -when added in very small quantities to a legitimate product- identify that product as the genuine article. Products made without these compounds are then identifiable as counterfeit when illuminated with an ultraviolet light.
8 Military uses are increasing rapidly. As the military continues to add more sensors and demands higher performance and more miniaturization, more rare earths –especially rare earth magnets- are used in more systems every day.
9 It’s not so well-known in North America, but one of the biggest uses of rare earth metals in the world is in electric bicycles, known as E-bikes. Rare Earth magnets allow the design of a motor that is integrated right into the hub of the rear wheel, so it is hardly even visible, and riders get a very long range from a very small battery since the motor is so efficient.
10 Rare Earth Metals are being used more and more in wind power. Neodymium-Iron-Boron (NdFeB) magnets are commanding a bigger share of the wind power turbine market as power density requirements increase and as customers demand lower maintenance requirements and lower lifecycle costs.
NdFeB magnets allow the use of direct drive systems that eliminate the need for a transmission, saving weight, volume and complexity in a nacelle that stands over 100 meters high. The reduction of weight and volume creates savings in many other parts of the design.
11 The oxide of Cerium is used to polish glass and ceramic parts. See how smooth the glass screen is on your mobile phone? You can thank cerium oxide.
12 Lanthanum compounds are used as chemical catalysts for a number of commercially important processes. They are found in some specialty kinds of glass and welding electrodes. Lanthanum is an alloying additive in steel and molybdenum.
Now You Know How Important They Are
Rare earth metals and compounds have become critically important in our high-tech world. They are in so many everyday items in our connected world that we touch and use products containing rare earth metals every day.