Dysprosium

Uses

Dysprosium’s most important modern role is as an additive to neodymium-iron-boron magnets — the strong permanent magnets found in electric vehicle motors, wind turbine generators, and hard disk drives. On its own, neodymium magnet material starts to lose its magnetism as it heats up, but blending in a small percentage of dysprosium makes it far more resistant to that high-temperature demagnetization, which matters a great deal inside a motor running hot under load. Dysprosium also absorbs neutrons effectively, so it’s used in some nuclear reactor control rod materials, and it contributes to Terfenol-D, the shape-changing alloy it shares with terbium.

Because of how central it is to high-performance magnets, dysprosium is closely watched as a “critical” rare earth — demand from electric vehicles and renewable energy has made reliable access to it a genuine strategic concern for manufacturers.

History

Dysprosium was isolated in 1886 by French chemist Paul-Émile Lecoq de Boisbaudran, who extracted it from holmium oxide after a long and painstaking series of chemical separations. Boisbaudran chose a name that reflected the ordeal: dysprosium comes from the Greek word for “hard to get at.” As with several other lanthanides discovered in this period, it took additional years of work by other chemists to confirm dysprosium as a genuinely distinct element and produce it in a reasonably pure form.