Gadolinium

Element Name: Gadolinium
Atomic Number: 64
Atomic Mass: 157.25
Atomic Symbol: Gd
Melting Point: 1313° C
Boiling Point: 3273° C

Gadolinium is a brittle, silvery-white rare earth metal which is soft, ductile, and malleable. Unlike other rare-earth metals, it is stable in dry air, but will form a white oxide when exposed to moist air. It has 27 known isotopes, but 158Gd is the most commonly occurring one. It is moderately toxic, but it is still used in medical procedures such as MRIs and MRAs that use chelated gadolinium compounds. At room temperature it is paramagnetic, but when cooled below 17° C it becomes ferromagnetic (and thus interacts with magnets). Gadolinium is most trivalent Gd3+.

Interesting Facts:

Gadolinium possession significant magnetocalorical properties (its temperature increases when entering a magnetic field and decreases when leaving one); this may have application in the field of room temperature magnetic refrigeration. It has unusually superconductive properties. Iron and Chromium, when imbued with as little as 1% gadolinium, gain improved resistance and workability. Gadolinium ethyl sulfate shows promise in duplicating the performance of amplifiers due to its low noise characteristics. Gadolinium has a Curie point of 19°C, which means if placed in a refrigerator it will become attracted to magnets, but when left to heat up it will no longer be affected.

Sources:

Gadolinium is never found free in nature, but contained in a number of minerals. Monazite, bastnaesite, gadolinite, cerite, and lerpersonnite-(Gd) all contain gadolinium. Ironically gadolinite contains very little gadolinium compared to the others. Like most rare-earth elements, Gadolinium requires a fairly involved process to separate into its elemental form from the minerals that contain it.

Industrial Uses:

Gadolinium has several specialized uses. Due to its incredibly high neutron cross-section (among stable nuclides) it’s used to target tumors in neutron therapy. In the CANDU type nuclear reactor it is used as an emergency shutdown because of its desirable shielding properties. Gadolinium is used in MRIs as an intravenous contrast agent. This is because it reacts to the magnetic field in an MRI and can show where blood is flowing (which is useful for finding internal bleeding). Gadolinium compounds are used to make green phosphors for TV tubes. Gadolinium yttrium garnet is a substance that has microwave applications and is used to make a variety of optical components. Doping materials like cerium oxide with gadolinium makes an electrolyte with high conductivity that can operate at low temperatures; this is useful in the production of fuel cells.

References:

“Gadolinium.” Chemicool Periodic Table. Chemicool.com, 17 Oct. 2012. Web. 26 July
2016.
“Gadolinium.” Wikipedia. Wikimedia Foundation, n.d. Web. 26 July 2016.
“Facts About Gadolinium.” Livescience. Livescience.com, 16 July. 2013. 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.