Lu_2(1-x)Ce_2x (SiO₄)

Cerium is a Block F, Group 3, Period 6 element. The number of electrons in each of Cerium's shells is 2, 8, 18, 19, 9, 2 and its electronic configuration is [Xe]4f² 6s². In its elemental form cerium's CAS number is 7440-45-1. The cerium atom has a radius of 182.5.pm and it's Van der Waals radius is 181.pm. Cerium is moderately toxic. Cerium is one of the products manufactured and distributed under the tradename AE Rare Earths. Cerium is the most abundant of the rare earths metals. It is characterized chemically by having two valence states , the +3 cerous and +4 ceric states. The ceric state is the only non-trivalent rare earth ion stable in aqueous solutions.It is, therefore, strongly acidic and moderately toxic. It is also a strong oxidizer.The cerous state closely resembles the other trivalent rare earths. The numerous commercial applications for cerium include metallurgy, glass and glass polishing, ceramics, catalysts, as the electrolyte for solid oxide fuel cells when doped with yttrium, gadolinium or samarium and in phosphors. In steel manufacturing it is used to remove free oxygen and sulfur by forming stable oxysulfides and by tying up undesirable trace elements, such as lead and antimony. It is considered to be the most efficient glass polishing agent for precision optical polishing. It is also used to decolor glass by keeping iron in its ferrous state. The ability of cerium-doped glass to block out ultra violet light is utilized in the manufacturing of medical glassware and aerospace windows. It is also used to prevent polymers from darkening in sunlight and to suppress discoloration of television glass. Cerium was first discovered by W. von Hisinger in 1903. The element was named after the asteroid Ceres. See Cerium research below.
 

• Crystal "pulling" by the Czochaiski method for production of semiconductor materials
• Flux growth and gradient freeze
• Directional solidification of fluorites using both the Bridgman-Stockbarger and float zoning techniques