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Dysprosium (Dy)
Dysprosium (symbol Dy) is the chemical element with atomic number 66: a lanthanide (rare earth), solid at 0 °C, with an atomic mass of 162.5 u. Discovered in 1886 (Paul-Émile Lecoq de Boisbaudran).
Dysprosium is the secret ingredient of magnets that must stay strong when hot, as in electric-car motors. A few percent is enough, but its deposits are rare and concentrated in China and Myanmar. It is one of the most closely watched raw materials of the energy transition.
Key facts
- Atomic number
- 66
- Symbol
- Dy
- French name
- Dysprosium
- Atomic mass
- 162.5 u
- Molar mass
- 162.5 g/mol
- Family
- Lanthanides
- Position
- period 6, f-block
- State at 0 °C
- Solid
- Melting point
- 1,406.9 °C
- Boiling point
- 2,566.9 °C
- Density
- 8.54 g/cm³
- Electronegativity (Pauling)
- 1.22
- First ionization energy
- 573 kJ/mol
- Atomic radius
- 175 pm
- Electron configuration
- [Xe] 4f¹⁰ 6s²
- Abundance in Earth's crust
- 5.2 ppm (42nd most abundant element)
- Indicative price
- 310 $/kg (order of magnitude)
- Radioactive
- no
- Discovery
- 1886, Paul-Émile Lecoq de Boisbaudran
Origin of the name
From the Greek dysprositos, “hard to get.”
What does dysprosium look like?
A bright silvery metal soft enough to cut, which tarnishes slowly in air.
Where is dysprosium found?
About 5 ppm of Earth's crust. It comes mainly from the ionic clays of southern China and northern Myanmar, and from xenotime.
Natural sources
- Xenotime
- Ion-adsorption clays
- Gadolinite
- Euxenite
How is dysprosium produced?
The clays are leached, then the elements are separated by solvent extraction; the metal is obtained by reducing the fluoride with calcium. Mining in Myanmar often causes severe environmental damage.
Top producers
- China
- Myanmar
- Australia
What is dysprosium used for?
- Heat-resistant NdFeB magnets (electric cars, wind turbines).
- Terfenol-D, together with terbium.
- Dosimeters that measure radiation exposure.
- Metal-halide lamps for stage lighting.
In everyday life
- An electric or hybrid car motor
- A hospital worker's dosimeter badge
Role in living things
No known biological role; mildly toxic.
Hazards of dysprosium
Low toxicity; flammable dust. The major impacts are environmental, linked to mining.
Cosmic origin
- Neutron stars: Created when two neutron stars collide — the “forge” of gold.
History of dysprosium
Lecoq de Boisbaudran isolated it as an oxide in 1886 after more than thirty successive precipitations, carried out, so the story goes, on the marble slab of his fireplace. Hence its name, from the Greek dysprositos, “hard to get at.” The pure metal wasn't obtained until the 1950s, by Frank Spedding at Iowa State University.
Did you know?
- An electric-car motor can contain anywhere from a few dozen to about a hundred grams of dysprosium.
- Manufacturers try to diffuse it only into the surface of the magnet grains to use less of it.
- Its atoms are among the most magnetic of all the elements.
Isotopes of dysprosium
Dysprosium has seven stable isotopes, with the heaviest ones (161 to 164) dominating by far.
- dysprosium-156: 0.056% of natural dysprosium, stable
- dysprosium-158: 0.095% of natural dysprosium, stable
- dysprosium-160: 2.329% of natural dysprosium, stable
- dysprosium-161: 18.889% of natural dysprosium, stable
- dysprosium-162: 25.475% of natural dysprosium, stable
- dysprosium-163: 24.896% of natural dysprosium, stable
- dysprosium-164: 28.26% of natural dysprosium, stable
- dysprosium-165: radioactive, half-life 2.33 h. Used to treat joint inflammation (radiosynovectomy).
- dysprosium-166: radioactive, half-life 3.4 days
Related elements
Same family (lanthanides): Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Holmium (Ho), Erbium (Er), Thulium (Tm), Ytterbium (Yb), Lutetium (Lu).