What is Gadolinium

Gadolinium (pronounced as GAD-oh-LIN-ee-em) is a soft metal belonging to the family of rare earth metals ^[1]. Denoted by the chemical symbol Gd, it has seven naturally-occurring isotopes of which Gadolinium-160 has the longest half-life ^[1].

Where is Gadolinium Found

Trace amounts of the element are present in monazite and bastnaesite minerals with an abundance of 6.2 mg/kg in the earth’s crust. It is commercially produced through ion exchange and solvent extraction using those minerals, and also by reducing anhydrous gadolinium fluoride with calcium ^[1].

History

Origin of its Name: It is named after the Finnish chemist and physicist Johan Gadolin.

Who Discovered Gadolinium: Jean Charles Galissard de Marignac was the discoverer of the element.

When and How was it Discovered

According to Marignac, he was sure about the existence of another element in the didymium mixture found by Carl Mosander, the Swedish chemist. When scientists Marc Delafontaine and Paul-Emile Lecoq de Boisbaudran at Paris analyzed the mixture, they found spectral lines that did not match with the source. In 1880, Marignac successfully isolated the new element from it followed by Boisbaudran in 1886 who named it gadolinium ^[1].

Gadolinium Identification
Atomic number	64 [1]
CAS number	7440-54-2 [1]
Position in the periodic table [1]	Group	Period	Block
	Lanthanides	6	f

Properties and Characteristics of Gadolinium

General Properties
Relative atomic mass	157.25 [1]
Atomic mass	157.25 atomic mass units [3]
Physical Properties
Color/appearance	Silver [1]
Melting point/freezing point	1313°C (2395°F) [1]
Boiling point	3273°C, 5923°C [1]
Density	7.90 g cm-3 [1]
State at normal room temperature (solid/liquid/gas)	Solid [1]
Chemical Properties
Oxidation state/Oxidation number		+1, +2, +3 [1]

Atomic Data of Gadolinium (Element 64)

What is Gadolinium Used for

• Iron and chromium alloys containing up to 1% of gadolinium have a greater resistance against oxidation and high temperature. Gd is also added to alloys used in magnets, storage disks, and electronic components ^[1].
• The ability of the element to capture neutrons makes it useful in control rods of nuclear reactors ^{[1, 2]}.
• Gadolinium is combined with yttrium to make garnets that have microwave applications ^[4].
• Gadolinium-based agents are used in MRI and CT scan procedures even though the element does not exhibit any radioactivity ^[8].

Toxicity and Dangers of Using Gadolinium

There is no information about any adverse risks on humans upon its exposure. However, in some instances, Gd-based MRI contrast agent has seemed to cause mild side effects like allergic reactions, nausea, and vomiting ^[3].

Interesting Facts

• Since gadolinium has magnetic properties, its temperature increases under the influence of magnetic field and decreases when withdrawn ^[7].

Gadolinium Price

The cost of the element may vary between $450 and $500 per 100 grams.

References
1. http://www.rsc.org/periodic-table/element/64/gadolinium
2. https://education.jlab.org/itselemental/ele064.html
3. https://pubchem.ncbi.nlm.nih.gov/compound/gadolinium#section=Computed-Properties
4. http://periodic.lanl.gov/64.shtml
5. http://periodictable.com/Properties/A/Valence.al.html
6. http://hobart.k12.in.us/ksms/PeriodicTable/gadolinium.htm
7. https://www.thoughtco.com/gadolinium-element-facts-606536
8. https://www.radiologymasterclass.co.uk/tutorials/mri/mri_gadolinium