Dysprosium

Dysprosium,  ₆₆Dy

General properties
Name, symbol	Dysprosium, Dy
Appearance	Silvery white
Dysprosium in the periodic table
- ↑ Dy ↓ Cf Terbium ← Dysprosium → Holmium
Atomic number	66
Standard atomic weight (Ar)	162.500(1)
Group, block	, f-block
Period	period 6
Electron configuration	[Xe] 4f10 6s2
per shell	2, 8, 18, 28, 8, 2
Physical properties
Silvery-white
Phase	Solid
Melting point	1680 K ​(1407 °C, ​​2565 °F)
Boiling point	2840 K ​(2562 °C, ​4653 °F)
Density near r.t.	8.54 g/cm3
when liquid, at	8.37 g/cm3
Heat of fusion	11.06 kJ/mol
Heat of	280 kJ/mol
Molar heat capacity	27.7 J/(mol·K)
pressure
Atomic properties
Oxidation states	4, 3, 2, 1 ​​(a weakly basic oxide)
Electronegativity	Pauling scale: 1.22
energies	1st: 573 kJ/mol 2nd: 1130 kJ/mol 3rd: 2200 kJ/mol
Atomic radius	empirical: 178 pm
Covalent radius	192±7 pm
Miscellanea
Crystal structure	​Hexagonal close-packed (hcp)
Speed of sound thin rod	2710 m/s (at 20 °C)
Thermal expansion	9.9 µm/(m·K) (α, poly)
Thermal conductivity	10.7 W/(m·K)
Electrical resistivity	926·10-9 Ω·m (at 20 °C) (α, poly)
Magnetic ordering	Paramagnetic
Young's modulus	61.4 GPa (α, poly)
Shear modulus	24.7 GPa (α, poly)
Bulk modulus	40.5 GPa (α, poly)
Poisson ratio	0.247 (α, poly)
Vickers hardness	410–550 MPa
Brinell hardness	500–1050 MPa
CAS Registry Number	7429-91-6
History
Discovery	Lecoq de Boisbaudran (1886)

Dysprosium is a chemical element with the symbol Dy and atomic number 66. It is a silvery metal that is very slightly magnetic.

Properties

Chemical

Dysprosium metal burns readily to form dysprosium(III) oxide:

4 Dy + 3 O₂ → 2 Dy₂O₃

Dysprosium metal will slowly react with water, and far more quickly with mineral acids, at room temperature to release hydrogen:

2 Dy + 6 H₂O → 2 Dy(OH)₃ + 3 H₂

However, dysprosium dissolves only slowly in weak acids, like acetic acid or citric acid, even when concentrated.

Physical

Dysprosium is a silvery lanthanide metal. It is soft enough to be scratched with a knife (though cutting it with a knife is time-consuming), and can be machined without sparking if overheating is avoided. Dysprosium and holmium have the highest magnetic strengths of the elements, especially at low temperatures. When cooled with liquid nitrogen, the metal turns ferromagnetic from its usual strong paramagnetic state.

Most dysprosium salts are highly paramagnetic. Some are also fluorescent.

Availability

Dysprosium is readily available from source such as Metallium and eBay. United Nuclear also sells metallic dysprosium, 10 g for 30 $. It is not cheap, but it is less expensive than gold or other precious metals.

Preparation

Metallic dysprosium can be prepared by reducing dysprosium halides with calcium or lithium. However, it is far more economical to just buy the metal.

Projects

• Make dysprosium(III) nitrate
• Make yellow fluorescent salts
• Dysprosium phthalate coordination polymer?
• Demonstration of paramagnetism

Handling

Safety

Dysprosium will react with water to produce hydrogen, which is flammable. Soluble dysprosium salts, such as dysprosium(III) chloride and dysprosium(III) nitrate, are mildly toxic when ingested. The insoluble salts, however, are non-toxic. Dysprosium fires require a class D fire extinguisher. Water may aggravate dysprosium fires or cause a hydrogen explosion.

Storage

Dysprosium can be stored in air indefinitely without any significant corrosion, likely due to passivation. Argon and mineral oil can be used to store it for very long periods of time. Water, acids, and any metal cleaning agent will tarnish dysprosium.

Disposal

As dysprosium is expensive, it's best to try to recycle it.

References

Relevant Sciencemadness threads

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