Marignac, a Swiss chemist, observed spectroscopic indications of samarium in a compound known as dydimia in 1853. However, it wasn´t until 1879 when Boisbaudran, a French chemist, isolated the element samarium from the mineral samarskite.
Samarium has a bright silver lustre and is reasonably stable in air but will ignite at 150°C. Even in long-term storage under mineral oil, samarium gradually oxidizes forming a grayish-yellow powder of oxides and hydroxides. The metallic appearance of a sample can be preserved by sealing it under an inert gas such as argon.
Today, samarium is primarily obtained through solvent extraction processes of both light and heavy rare earth minerals, and the major source is The People´s Republic of China.
APPLICATION OF SAMARIUM
Magnets and Electronics: SmCo5 and Sm2Co17 alloys are used in making ´Samarium-cobalt´ permanent magnets that have a high resistance to demagnetization when compared to other permanent magnet materials. Although these magnets are expensive, their high working temperatures make them irreplaceable in high temperature environments found in some hybrid electric automobiles. Samarium-cobalt magnets are also used in high-end magnetic pickups for guitars and related electronic musical instruments, headphone magnets and automotive accessories where light weight low energy consumption, and physical size are important considerations.
Samarium in form of titanates has a high dielectric property useful in capacitors at microwave frequencies, and because of its spectral absorption properties it is used in neodymium-yttrium-aluminum garnet laser glass.
Medicine: Samarium-153, a radioisotope of samarium, is used in medicine to treat the severe pain associated with cancers that have spread into bone tissues. The drug is called ´Quadramet´
Other uses: Samarium compounds act as sensitizers for phosphors excited in the infrared and samarium oxide (Sm2O3) is added to glass to absorb infrared radiation.
Samarium also makes up about 1% of Mischmetal, an alloy of the rare earths lanthanum, cerium and neodymium used to make flints for lighters. Samarium oxide is also a catalyst for the dehydration and dehydrogenation of ethanol, and as a chemical reagent in organic synthesis.
LINKS: For chemical and physical properties: www.webelements.com or http://education.jlab.org/itselemental/ele062.html
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