Living Reference Work Entry

Encyclopedia of Geochemistry

Part of the series Encyclopedia of Earth Sciences Series pp 1-3

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Samarium

  • Michael BizimisAffiliated withEarth and Ocean Sciences, University of South Carolina Email author 
  • , Howie ScherAffiliated withEarth and Ocean Sciences, University of South Carolina Email author 

Properties

Element Data

Atomic symbol: Sm

Atomic number: 62

Atomic weight: 150.363(8)

Isotopes and abundances:

Sm 3.08(1)

Sm 15.02(5)%

Sm 11.25(3)%

Sm 13.83(4)%

Sm 7.35(2)%

Sm 26.74(3)%

Sm 22.73(5)%

1 atm melting point: 1345 K

1 atm boiling point: 2067 K

Common valences: 3+

Ionic radii: 108 pm (eightfold coordination)

Pauling electronegativity: 1.17

First ionization potential: 5.6437 eV

Chondritic (CI) abundance: 0.148 ppm

Silicate Earth abundance: 0.406 ppm

Crustal abundance: 3.9 ppm

Seawater abundance: 0.1–20 pmol/kg

Core abundance: ~0

History and Use

Samarium was first discovered by Swiss chemist Marc Delafontaine in 1878 who named it “decipium,” later proven to be a mixture of samarium and other rare earths. French chemist Paul-Emile Lecoq de Boisbaudran isolated samarium in 1879. It was purified from the mineral samarskite named for Colonel Vasili von Samarsky, a Russian mine official (Holden, 2001). Commercial applications of Sm include samarium-cobalt magnets, which have a permane ...

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