Discovered | Name | Characteristics | Uses

Samarium metal is in the lanthanide series of elements, which stretches from lanthanum (La) through lutetium (Lu). Like many of these elements, it has common oxidation numbers of +2 and +3.

Like cesium, rubidium, thallium, and indium, Sm was discovered spectroscopically. It was found by Lecoq de Boisbaudran in 1879 in the mineral samarskite, which had been named in honor of a Russian mine official. Its commercial sources today, like most of the other lanthanides, are the minerals monazite and bastnasite.

The metal has a bright silvery luster. However, it does oxidize in air, particularly above 150°C, to give samarium(III) oxide, Sm2O3.

An alloy with cobalt, SmCo5, has been used to make permanent magnets with the higest resistance to demagnetization of any know material. Such magnets are used in headphones and tape drives.