Ytterbium (Yb)

Ytterbium (symbol Yb) is the chemical element with atomic number 70: a lanthanide (rare earth), solid at 0 °C, with an atomic mass of 173.05 u. Discovered in 1878 (Jean Charles Galissard de Marignac).

Ytterbium lies at the heart of very powerful fiber lasers used for industrial cutting and welding. Its atoms, trapped by light, form some of the most stable atomic clocks ever built. Like three other elements, it is named after the small Swedish village of Ytterby.

Key facts

Atomic number: 70
Symbol: Yb
French name: Ytterbium
Atomic mass: 173.05 u
Molar mass: 173.05 g/mol
Family: Lanthanides
Position: period 6, f-block
State at 0 °C: Solid
Melting point: 823.9 °C
Boiling point: 1,195.9 °C
Density: 6.9 g/cm³
Electronegativity (Pauling): 1.1
First ionization energy: 603 kJ/mol
Atomic radius: 175 pm
Electron configuration: [Xe] 4f¹⁴ 6s²
Abundance in Earth's crust: 3.2 ppm (45th most abundant element)
Indicative price: 17 $/kg (order of magnitude)
Radioactive: no
Discovery: 1878, Jean Charles Galissard de Marignac

Origin of the name

From Ytterby, a Swedish village.

What does ytterbium look like?

A bright, soft, ductile silvery metal that tarnishes slowly in air.

Where is ytterbium found?

About 3 ppm of Earth's crust. It is found in xenotime, euxenite, gadolinite and ionic clays.

Natural sources

Xenotime
Gadolinite
Euxenite
Ion-adsorption clays

How is ytterbium produced?

Separated by ion exchange or solvent extraction; the metal is obtained by reducing its oxide with lanthanum, then distilling it.

Top producers

China
Myanmar

What is ytterbium used for?

Ytterbium-doped fiber lasers for cutting and welding metals.
Optical atomic clocks.
Strain gauges for measuring very high pressures (explosions, earthquakes).
Doping certain stainless steels.

In everyday life

A laser-cut car body panel
Laser marking on a metal object

Role in living things

No known biological role.

Hazards of ytterbium

Low toxicity, but its compounds can irritate the skin and eyes; flammable dust.

Cosmic origin

Neutron stars: Created when two neutron stars collide — the “forge” of gold.
Dying stars: Made slowly in red giants (stars like the Sun at the end of their lives).

History of ytterbium

The Swiss chemist Jean Charles Galissard de Marignac identified it in 1878 in erbia. In 1907 Georges Urbain showed that this “ytterbium” actually contained two elements, one of them lutetium.

Did you know?

In 2013, an ytterbium clock at the US NIST set a stability record: it would drift by only one second over several billion years.
The Ytterby mine was designated a historical landmark by the American Society for Metals in 1989.
Its electrical resistance changes with pressure, making it a sensor for shock waves.

Isotopes of ytterbium

Ytterbium has seven stable isotopes. Ytterbium-171 ticks at the heart of some of the most precise atomic clocks in the world.

ytterbium-168: 0.123% of natural ytterbium, stable
ytterbium-169: radioactive, half-life 32 days. A gamma source for radiographing thin parts and for brachytherapy.
ytterbium-170: 2.982% of natural ytterbium, stable
ytterbium-171: 14.09% of natural ytterbium, stable. Used in optical atomic clocks of extreme precision.
ytterbium-172: 21.68% of natural ytterbium, stable
ytterbium-173: 16.103% of natural ytterbium, stable
ytterbium-174: 32.026% of natural ytterbium, stable
ytterbium-175: radioactive, half-life 4.19 days
ytterbium-176: 12.996% of natural ytterbium, stable. Irradiated in reactors to produce very pure lutetium-177 for medical use.

Related elements

Same family (lanthanides): Lanthanum (La), Cerium (Ce), Praseodymium (Pr), Neodymium (Nd), Promethium (Pm), Samarium (Sm), Europium (Eu), Gadolinium (Gd), Terbium (Tb), Dysprosium (Dy), Holmium (Ho), Erbium (Er), Thulium (Tm), Lutetium (Lu).