Specifications: Lutetium Lutetium is a chemical element with the symbol Lu and atomic number 71. A metallic element, lutetium usually occurs in association with yttrium and is sometimes used in metal alloys and as a catalyst in various processes. A strict correlation between periodic table blocks and chemical series for neutral atoms would describe lutetium as a transition metal because it is in the d-block, but it is a lanthanide according to IUPAC.[1] Lutetium is a silvery white corrosion-resistant trivalent metal that is relatively stable in air. Lutetium 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. This element is very expensive to obtain in useful quantities and therefore it 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. Lutetium-176 (176Lu) has been used to date the age of meteorites. Lutetium aluminum 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 tumours. Cerium-doped lutetium oxyorthosilicate (LSO) is currently the preferred compound for detectors in positron emission tomography (PET.).
