Editorial Feature

Samarium (Sm) - Discovery, Occurrence, Production, Properties, and Applications

Samarium was first observed spectroscopically by a Swiss chemist, Jean Charles Galissard de Marignac in 1853 while working with dydimia. Paul-Émile Lecoq de Boisbaudran, a French chemist first isolated samarium along with didymium from the mineral samarskite in 1879. The element derived its name from the mineral samarskite from which it was isolated.

Basic Information

Name Samarium
Symbol Sm
Atomic number 62
Atomic weight 150.36 amu
Standard state Solid at 298 K
CAS Registry ID 7440-19-9
Group name Lanthanoid
Period in periodic table 6
Block in periodic table f-block
Color Silvery white
Classification Metallic
Melting point 1347 K (1074°C or 1965°F)
Boiling point 2067 K (1794°C or 3261°F)
Density 7.52 g/cm3
Phase at room temperature Solid

Occurrence

Samarium is present in rare earth ores including samarskite, bastnaesite and monazite.

Samarium - Periodic Table of Videos

Isotopes

It has 30 isotopes with mass numbers ranging from 131Sm to 160Sm. It consists of seven naturally-occurring isotopes that include 144Sm, 147Sm, 148Sm, 149Sm, 150Sm, 152Sm and 154Sm.

Production

Pure samarium can be produced by electrolyzing the molten chloride with sodium chloride. In addition, it can be commercially recovered from bastnaesite and monazite sand with the help of ion exchange and solvent extraction techniques.

Key Properties

The following are the key properties of samarium:

  • It is a bright, hard silvery metal
  • It exists in its trivalent state
  • It is stable in air at normal temperatures
  • It forms oxide with moist air
  • It is the hardest and most brittle rare earth element.

Applications

The applications of samarium include the following:

  • It is used as a catalyst for dehydrogenating and dehydrating ethanol
  • 153Sm is used to treat cancer owing to its radioactivity
  • It is mainly used in preparing samarium-cobalt alloy magnets for electric guitars, small motors and headphones
  • It is used as an absorber in nuclear reactors
  • Its oxide is used for manufacturing special infrared adsorbing glass for carbon arc-lamp electrodes
  • It is useful in doping calcium fluoride crystals employed in optical lasers.

Sources and Further Reading

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