Dysprosium (Dy)
“The rare earth whose Greek name means “hard to get at” — and the secret ingredient that keeps electric-car magnets alive in motor heat.”
How its electrons are arranged
Computed from the aufbau principle, with known real-world exceptions applied automatically.
The notes
Characteristics
- Electron configuration [Xe] 4f¹⁰ 6s²; like almost every lanthanide it hands over three electrons to become Dy³⁺ ([Xe] 4f⁹), holding a firm +3 oxidation state.
- Its magnetic susceptibility ranks among the very highest of all the elements, and chilled below about 88 K (−185 °C) the metal finally orders itself into a ferromagnet.
- Strongly magnetostrictive — in changing magnetic fields dysprosium-rich alloys physically stretch and shrink, a movement engineers convert into sound and precision motion.
- A zealous absorber of slow neutrons, which is why nuclear engineers seat dysprosium compounds where chain reactions need taming.
A soft, silvery metal that keeps its polish only briefly in dry air before slowly clouding, and one of the heavier rare earths. Its chemistry wears a yellow tint: Dy³⁺ salts and the oxide dress laboratory glassware in pale yellow hues.
Where you meet it
✦ Uses
- Heat-proofing neodymium super-magnets: a few percent of dysprosium in the Nd-Fe-B alloy keeps the magnets of electric-vehicle motors and wind-turbine generators from demagnetising when they run hot.
- Terfenol-D — the terbium–dysprosium–iron magnetostrictive alloy at the heart of naval sonar transducers and vibration-free precision actuators.
- Neutron-hungry control rods: dysprosium titanate and dysprosium-oxide cermets tame chain reactions in nuclear reactors, including Russia’s VVER fleet.
- Dysprosium iodide inside metal-halide discharge lamps — the roaring “daylight” that film and studio crews light night scenes with.
◍ Everyday examples
- Every hybrid or battery-electric car — a slowly growing sight on Dhaka’s roads — carries roughly a hundred grams of dysprosium hidden in its traction-motor magnets.
- A film crew lighting a night scene with “daylight” lamps, and a warship sweeping the sea with sonar, both lean on dysprosium without ever billing it.
History & name
In Paris in 1886 the French spectroscopist Paul-Émile Lecoq de Boisbaudran ground through more than thirty rounds of painstaking fractional crystallisation on holmium oxide before an unknown element finally showed its spectral lines. He named it dysprosium, from the Greek dysprositos — “hard to get at” — and the name proved prophetic: reasonably pure metal was not achieved until the 1950s, when Frank Spedding’s ion-exchange team at the Ames Laboratory in Iowa cracked the lanthanide separation problem for good.