PTL:Gadolinium
From ChemEd Collaborative
| Symbol: | Gd |
|---|---|
| Atomic Number: | 64 |
| Atomic Weight: | 157.251(3) |
| Electron Configuration: | [Xe] 4f8 6s2 |
| Atomic Radius: | 180.2pm |
| Melting Point: | 1313°C |
| Boiling Point: | 3273°C |
| Heat of Fusion: | 10.05kJ/mol |
| Heat of Vaporization: | 359.4kJ/mol |
| Specific Heat Capacity: | 0.23J/gK |
Gadolinium is a member of the lanthanide series of elements, which stretches from lanthanum (La) through lutetium (Lu).
Contents |
Discovered
As with other lanthanides, Marignac and Lecoq de Boisbaudran were involved in the discovery of Gd. Marignac thought that the widely studied rare earth didymia was a mixture of elements rather than an oxide of a single metal, but he was unable to find a new element. However, de Boisbaudran was able to isolate element 64 from didymia in 1879 using some of de Marignac's ideas. Gadolinium is named for gadolinite, the mineral from which it was first obtained.
Characteristics
It is a soft, ductile metal with a silvery appearance. In the solid state, the metal has a hexagonal closest packed structure. Gadolinium is ferromagnetic, and its Curie temperature (temperature above which ferromagnetism disappears) is about room temperature. Some isotopes of gadolinium have excellent neutron capture properties, but they occur in too low concentrations to be useful. It is relatively stable, but oxidizes when exposed to air. It is also soluble in dilute acid.
Prepared
The metal is obtained by reducing a halide with an "active" metal such as Ca or Li.
3 Li(s) + GdCl3(s) 
Gd(s) + 3 LiCl(s)
Uses
The reaction is carried out in a tantalum crucible at high temperature in a helium atmosphere (the latter being used to prevent oxidation of the metal).
In spite of its low abundance in the earth's crust, the element is used in making [steel] alloys and in the manufacture of electrical components. In addition, [a garnet made of gadolinium and gallium is used for "bubble memories"] in computers. And finally, since Gd is perhaps the best of the naturally occurring elements in absorbing neutrons, it is used in the [control rods in nuclear reactors].
Emission Spectra
This is the emission spectra for Gadolinium.
