3. Rare Earth Metals: Any of group of chemically similar metallic
elements comprising the lanthanide series (usually) scandium and yttrium are
called rare earth metals.
They are not specially rare, but they tend to occur together in nature and are
difficult to separate from one another. So, they are also called rare earth
elements.
4. Gadolinium
Element name: Gadolinium
Atomic Number: 64
Symbol: Gd
Atomic Weight: 157. 25
Discovery: Jean de Marignac 1880 (Switzerland)
Electron Configuration: [Xe] 4f7 5d1 6s2
Element Classification: Rare earth (Lanthanide)
Word Origin: Named after the mineral
Gadolinite.
Melting point (K) : 1586
Boiling Point (K) : 3539
Oxidization States: 3
Lattice Structure: Hexagonal
5. Major Characteristics of Gadolinium
1.Gadolinium is silvery, malleable, ductile metal with a mettalic sheen. It is
fluorescent and tends to have a faintly yellowish tint.
2. Like other rare earth elements, it is not found in pure form in nature. The
primary source of the element is the mineral gadolinite. It is also found in
other rare earth ores, such as monazite and bastnasite.
3. At low temperatures, gadolinium is more ferromagnetic than iron.
4. Gadolinium has superconductive properties.
5. Gadolinium is magnetocaloric, which means its temperature increases
when it is placed in a magnetic field and decreases when it is removed from
the field.
6. Gadolinium has the highest thermal neutron cross-section of all the
elements.
7. The pure metal is fairly stable in air but tarnishes in moist air. It slowly
reacts in water and dissolves in dilute acid. At high temperature gadolinium
reacts with oxygen.
