Dysprosium
Atomic Data
| Atomic Number | 66 |
| Symbol | Dy |
| Atomic Weight | 162.5 u |
| Density (STP) | 8.551 g/cm³ |
| Melting Point | 1406.85 °C (1680 K) |
| Boiling Point | 2566.85 °C (2840 K) |
| Electronegativity | 1.22 (Pauling) |
| Electron Config. | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f10 5s2 5p6 6s2 |
| Oxidation States | +3 |
| Phase at STP | Solid |
| Category | Lanthanoid |
| Period / Group | 6 / None |
| CAS Number | 7429-91-6 |
Electron Configuration
[Xe] 4f10 6s2
| Shell | n | Subshell | Electrons | Cumulative |
|---|---|---|---|---|
| K | 1 | 1s | 2 | 2 |
| L | 2 | 2s | 2 | 4 |
| L | 2 | 2p | 6 | 10 |
| M | 3 | 3s | 2 | 12 |
| M | 3 | 3p | 6 | 18 |
| M | 3 | 3d | 10 | 28 |
| N | 4 | 4s | 2 | 30 |
| N | 4 | 4p | 6 | 36 |
| N | 4 | 4d | 10 | 46 |
| N | 4 | 4f | 10 | 56 |
| O | 5 | 5s | 2 | 58 |
| O | 5 | 5p | 6 | 64 |
| P | 6 | 6s | 2 | 66 |
| Total | 66 | 66 | ||
Isotopes of Dysprosium
Dysprosium has three naturally occurring stable isotopes. The most abundant is ¹⁶⁴Dy, comprising 28.18% of all naturally occurring Dysprosium.
| Isotope | Symbol | Protons | Neutrons | Abundance | Stability |
|---|---|---|---|---|---|
| Dysprosium-162 | ¹⁶²Dy | 66 | 96 | 25.51 | Stable |
| Dysprosium-163 | ¹⁶³Dy | 66 | 97 | 24.9 | Stable |
| Dysprosium-164 | ¹⁶⁴Dy | 66 | 98 | 28.18 | Stable |
Abundance & Occurrence
Dysprosium is present in Earth's crust at approximately 5.2 ppm by mass and at approximately 0.2 ppm by mass throughout the universe.
Earth's Crust (ppm by mass)
Universe (ppm by mass)
Discovery & History
Read more about the discovery of the periodic table of elements →
Safety & Handling
- Dust inhalation: Dysprosium metal dust and oxide are respiratory irritants; occupational handling with dust controls and appropriate respiratory protection is required for machining and powder operations.
- Fire hazard: Dysprosium metal powder is flammable; metal fires require Class D extinguishing agents.
- Magnet handling: Dysprosium-containing NdFeB magnets are powerful and can cause crush injuries; keep clear of ferromagnetic objects and active medical devices (pacemakers).
- General toxicity: Dysprosium is considered to have low acute systemic toxicity; the primary hazard is inhalation of dust during processing.
Dysprosium in the Real World
Real-World Uses
- Nd-Fe-B magnet coercivity enhancement: Dysprosium (2–6%) is added to neodymium iron boron permanent magnets to increase coercivity at elevated temperatures, enabling the magnets to function reliably in electric vehicle traction motors that reach 150 °C or more.
- Wind turbine generator magnets: Direct-drive wind turbines use large Dy-containing Nd-Fe-B magnets because the magnets must retain high coercivity under the variable-temperature conditions of outdoor wind farm operation over a 25-year service life.
- Nuclear reactor control rods: Dysprosium titanate and dysprosium oxide pellets are used as burnable neutron absorbers in some reactor designs; Dy-164 has a high thermal neutron capture cross-section effective for reactivity control.
- Radiation dosimetry: Dysprosium-activated calcium sulfate (CaSO₄:Dy) thermoluminescent dosimetry (TLD) chips measure accumulated radiation doses received by workers in nuclear power plants, medical facilities, and research laboratories.
Downloadable Resources
Free periodic table reference sheets for classrooms, study sessions, and laboratory use.
Frequently Asked Questions
What is dysprosium used for?
Dysprosium is primarily used to improve the high-temperature performance of neodymium-iron-boron permanent magnets. Adding a few percent dysprosium raises the magnets' coercivity (resistance to demagnetisation at high temperatures), which is critical for electric vehicle motors and wind turbine generators that operate warm. Dysprosium is also a component of Terfenol-D and is used in neutron-absorbing control rods in some nuclear reactors.
Why is dysprosium critical for electric vehicles?
The motors in electric vehicles use NdFeB permanent magnets that must maintain their magnetic properties at elevated operating temperatures. Without dysprosium additions, these magnets can demagnetise when the motor heats up. Adding 2–6% dysprosium extends the operating temperature range significantly, but dysprosium is scarce and expensive. This has driven research into dysprosium-free motor designs and recycling strategies for rare-earth magnets.
How was dysprosium discovered?
Dysprosium was discovered in 1886 by French chemist Paul Emile Lecoq de Boisbaudran, who isolated it from holmia (holmium oxide) after an extraordinarily tedious series of 32 fractional precipitations. He named it dysprosium from the Greek 'dysprositos', meaning hard to get: a fitting tribute to the difficulty of its isolation.
Is dysprosium radioactive?
Natural dysprosium is not radioactive. It consists of seven stable isotopes, with Dy-164 being the most abundant (28.2%). Some artificial dysprosium isotopes are radioactive, but elemental dysprosium as encountered in magnets, alloys, and industrial applications poses no radiation hazard.