Ytterbium

Element Name: Ytterbium
Atomic Number: 70
Atomic Mass: 173.054
Atomic Symbol: Yt
Melting Point: 819° C
Boiling Point: 1196° C

Ytterbium was given its name by Jean Charles Galissard de Marignac in 1878, but in his discovery was realized to be 2 separate elements in 1907. The first to discover ytterbium is disputed, but Georges Urbain is the one credited for it. It’s a bright silver rare earth element which is ductile, soft, and malleable. Ytterbium has three allotropes, and surprisingly the one it has at room temperature is different than the ones most lanthanides have (Face-centered cubic and close-packed hexagonal lattice, respectively). This causes it to have significantly lower density and a relatively low melting and boiling point when compared to the other lanthanides. Ytterbium has 7 stable isotopes which occur in nature and another 27 radioscopes that have been made synthetically. Much like europium and samarium, ytterbium has a valid 2+ state.

Interesting Facts:

Ytterbium has the smallest liquid range (difference between boiling and melting points) of any metal. Carl Auer von Welsbach contested Georges Urbain in the discovery of ytterbium and lutetium, but the Commision on Atomic Mass (who were responsible for deciding which names and discoveries were credited) sided with Urbain. Urbain held one of the three seats on the commission. When placed under pressure ytterbium’s electrical resistance spikes dramatically. It’s for this reason that ytterbium is used in stress gauges to sense earthquakes and underground explosions. An optical clock uses ytterbium ions to keep track of time to remarkable accuracy. The ticks of a ytterbium clock are accurate to 2 parts in quintillion of a second (that is to say 2 x 10-18s); if you used this sort of clock to measure the time between the beginning of the universe and now you could expect to have an error no greater than a second. Ytterbium oxide emits more in the infrared spectrum than magnesium oxide making it a prime candidate for use in decoy flares.

Sources:

Ytterbium is never found in its elemental form in nature. Several minerals hold varying quantities of ytterbium, including monazite, bastnasite, xenotime, euxenite, and gadolinite. It is found in 3 parts per million, making it fairly rare. Only 50 tons of ytterbium is mined every year which is a reflection of how few applications it has.

Industrial Uses:

Alloying ytterbium with stainless steel to help the strength, grain refinement, and other mechanical properties. Ytterbium-160 is radioactive and has been used in portable x-ray machines; radiographs taken with Ytterbium-169 are an accurate comparison to radiographs taken by x-rays having between 250 and 350 keV. Ytterbium also sees use as a dopant in lasers and fiber optics (albeit at fairly small levels – large amounts of ytterbium causes a photodarkening effect). It also sees use as a catalyst in organic chemistry.

References:

“Facts About Ytterbium.” Livescience. Livescience.com, 24 July 2013. Web. 26 July
2016.
“Ytterbium.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Ytterbium Element Facts / Chemistry.” Chemicool. Chemicool.com, 18 Oct. 2012.
Web. 26 July 2016.
Gray, Theodore W., and Nick Mann. The Elements: A Visual Exploration of Every
Known Atom in the Universe. New York: Black Dog & Leventhal, 2009. Print.