Lutetium is a chemical element with the symbol Lu
and atomic number 71. It is in the d-block of the
periodic table, not the f-block, but the IUPAC classifies it as a
lanthanide. It is one of the elements that traditionally were
included in the classification, "rare earths". One of its
radioactive isotopes (176Lu) is used in nuclear
technology to determine the age of meteorites. Lutetium usually
occurs in association with the element yttrium and is sometimes
used in metal alloys and as a catalyst in various chemical
reactions.
What Lutetium looks like.
Physical properties
Lutetium is a silvery white corrosion-resistant trivalent metal. It
has the smallest atomic radius and is the heaviest and hardest of
the rare earth elements. Lutetium has the highest melting point of
any lanthanide, probably related to the lanthanide contraction.
Occurrence and production
Found with almost all other rare-earth metals but never by itself,
lutetium is very difficult to separate from other elements. The
principal commercially viable ore of lutetium is the rare earth
phosphate mineral monazite: (Ce, La, etc.) PO4 which
contains 0.003% of the element. The abundance of lutetium in the
Earth crust is only about 0.5 mg/kg. The main mining areas are
China, United States, Brazil, India, Sri Lanka and Australia. The
world production of lutetium (in the form of oxide) is about 10
tonnes per year. Pure lutetium metal has only relatively recently
been isolated and is very difficult to prepare. It is one of the
rarest and most expensive of the rare earth metals with the price
about US$ 10,000 per kg, or about one-fourth that of Gold.
Applications
Because of the rarity and high price, lutetium has very few
commercial uses. However, stable lutetium can be used as catalysts
in petroleum cracking in refineries and can also be used in
alkylation, hydrogenation, and polymerization applications.
Some other applications include:
Lutetium-176 (176Lu) has been used to date the age of
meteorites.
Lutetium aluminium garnet
(Al5Lu3O12) has been proposed for
use as a lens material in high refractive index immersion
lithography.
Lutetium-177 (177Lu), when bound to Octreotate (a
somatostatin analogue), is used experimentally in targeted
radionuclide therapy for neuroendocrine tumors.
Cerium-doped lutetium oxyorthosilicate (LSO) is currently the
preferred compound for detectors in positron emission tomography
(PET.)
Use as a pure beta emitter, using lutetium which has been exposed
to neutron activation. A tiny amount of lutetium is added as a
dopant to gadolinium gallium garnet (GGG), which is used in
magnetic bubble memory devices.
Precautions
Like other rare-earth metals, lutetium is regarded as having a low
degree of toxicity, but its compounds should be handled with care
nonetheless. Metal dust of this element is a fire and explosion
hazard. Lutetium plays no biological role in the human body.
PERIODIC TABLE
Check out this interactive Periodic Table.
Check out this Lutetium video. Prepared by The University of
Nottingham.