Return to periodic table H' at. Discovered spectroscopically by its sharp absorption lines in 1879 by Lecoq de Bois- baudran in the mineral samarskite, named in honor of a Russian mine official, Col. Samarski. Samarium metal can be produced by re- ducing the oxide with barium or lanthanum. Samarium has a bright silver luster and is reasonably stable in air. The metal ignites in air at about 1 500C. Sixteen isotopes of samarium exist.
Natural samarium is a mixture of seven isotopes, four of which are unstable with long half-lives.
The sulfide has excellent high-temperature stability and good thermoelectric efficiencies up to 1 1000C. SmCO5 has been used in making a new permanent magnet material with the highest resistance to demagnetization of any known material. It is said to have an intrinsic coercive force as high as 28,000 oersteds. Samarium oxide has been used in optical glass to absorb the infrared. Sarnarium is used to dope calcium fluoride crystals for use in optical masers or lasers. It is used in infrared absorbing glass and as a, neutron ab- sorber in nuclear reactors.