Samarium

Description

Standard State: solid at 298 K
Color: Silvery white

Discovered spectroscopically by its sharp absorption lines in 1879 by Lecoq de Boisbaudran in the mineral samarskite, named in the honor of a Russian mine official, Col. Samarski. Samarium is found along with other members of the rare earth elements in many minerals, including monazite and bastnasite, which are commercial sources. Samarium metal can produced by reducing the oxide with barium or lanthanum. Samarium has a bright silver luster and is reasonably stable is air.  The metal ignites in air at about 150°C. Samarium is used to dope calcium fluoride crystals for use in optical masers or lasers.   Compounds of the metal act as sensitizes for phosphors excited in the infrared; the oxide exhibits catalytic properties in the dehydration and dehydrogenation of ethyl alcohol.  It is used in infrared absorbing glass and as a neutron absorber in nuclear reactors.