Author: Jan Scholten
8.0 Samarium physical
Samarium is a rare earth metal, with a bright silver lustre, that is reasonably stable in air; it ignites in air at 150°C. Three crystal modifications of the metal also exist, with transformations at 734 and 922°C, respectively.
Atomic Number: 62.
Discovery: 1879 by P.É. Lecoq de Boisbaudran at Paris, France.
Name: Russian mine official, colonel Samarski; like the mineral.
Toxicilogy: Mildly toxic by ingestion: skin and eye irritant; stimulates metabolism.
Ore: Samarskit: ULaNaNbFe2O3.
1. Carbon-arc lighting for the motion picture industry (together with other rare earth metals).
2. Lasers; Doping CaF2 crystals for use in optical masers or lasers.
3. Samarium oxide is used in optical glass to absorb infrared light.
4. Samarium compounds act as sensitizers for phosphors excited in the infrared.
5. Magnets: SmCo5 is a strong magnet, 20 MGOe, the most used magnet in small electric motors, walkman, sensors. Samarium-Cobalt magnets; SmCo5 is used in making a new permanent magnet material with the highest resistance to demagnetization of any known material, and an intrinsic coercive force as high as 2200 kA/m.
6. Magnets: Sm2Co17 is a strong magnet, 30 MGOe, but is more expensive.
7. Alloys and headphones.
8. Samarium oxide is a catalyst for the dehydration and dehydrogenation of ethanol.
9. Neutron absorber in nuclear reactors.