Samarium

Samarium is a <a href="/facts/Chemical_element/0jducgWD">chemical element</a>; it has <a href="/facts/Chemical_symbol/2Fe1VAL0">symbol</a> Sm and <a href="/facts/Atomic_number/bgAr581S">atomic number</a> 62. It is a moderately hard silvery <a href="/facts/Metal/pqQVs8QU">metal</a> that slowly oxidizes in air. Being a typical member of the <a href="/facts/Lanthanide/rt3XIRCl">lanthanide</a> series, samarium usually has the <a href="/facts/Oxidation_state/W53W6s6V">oxidation state</a> +3. Compounds of samarium(II) are also known, most notably the <a href="/facts/Monoxide/Bwols155">monoxide</a> SmO, <a href="/facts/Samarium_monochalcogenides/h7Q8Nce2">monochalcogenides</a> SmS, SmSe and SmTe, as well as <a href="/facts/Samarium(II)_iodide/aCE3R3Jz">samarium(II) iodide</a>.
Discovered in 1879 by French chemist <a href="/facts/Paul-%25C3%2589mile_Lecoq_de_Boisbaudran/XT2EnBwI">Paul-Émile Lecoq de Boisbaudran</a>, samarium was named after the mineral <a href="/facts/Samarskite/q79Axajv">samarskite</a> from which it was isolated. The mineral itself was named after a Russian mine official, Colonel <a href="/facts/Vassili_Samarsky-Bykhovets/AYuKW2ot">Vassili Samarsky-Bykhovets</a>, who thus became the first person to have a chemical element named after him, though the name was indirect.
Samarium occurs in concentration up to 2.8% in several minerals including <a href="/facts/Cerite/KJvUo0Er">cerite</a>, <a href="/facts/Gadolinite/kahQI57c">gadolinite</a>, samarskite, <a href="/facts/Monazite/an71GkIH">monazite</a> and <a href="/facts/Bastn%25C3%25A4site/wSaG43h8">bastnäsite</a>, the last two being the most common commercial sources of the element. These minerals are mostly found in China, the United States, Brazil, India, Sri Lanka and Australia; China is by far the world leader in samarium mining and production.
The main commercial use of samarium is in <a href="/facts/Samarium%25E2%2580%2593cobalt_magnet/Qcr5aIBr">samarium–cobalt magnets</a>, which have permanent <a href="/facts/Magnet/vvrg6VSk">magnetization</a> second only to <a href="/facts/Neodymium_magnet/1LApJ5Xq">neodymium magnets</a>; however, samarium compounds can withstand significantly higher temperatures, above 700 °C (1,292 °F), without losing their permanent magnetic properties. The <a href="/facts/Radioisotope/5WpCfbdq">radioisotope</a> samarium-153 is the active component of the drug <a href="/facts/Samarium_(153Sm)_lexidronam/HoM2yUNN">samarium (153Sm) lexidronam</a> (Quadramet), which kills cancer cells in <a href="/facts/Lung_cancer/LHLdR454">lung cancer</a>, <a href="/facts/Prostate_cancer/Mx7XuDhm">prostate cancer</a>, <a href="/facts/Breast_cancer/6hME580v">breast cancer</a> and <a href="/facts/Osteosarcoma/FnlFbprC">osteosarcoma</a>. Another isotope, <a href="/facts/Samarium-149/e5wQw5B0">samarium-149</a>, is a strong <a href="/facts/Neutron/oRCM1geb">neutron</a> absorber and so is added to <a href="/facts/Control_rod/VvMTweU5">control rods</a> of <a href="/facts/Nuclear_reactor/8xqjIbge">nuclear reactors</a>. It also forms as a decay product during reactor operation and is one of the important factors considered in reactor design and operation. Other uses of samarium include <a href="/facts/Catalysis/LPBS7TQC">catalysis</a> of <a href="/facts/Chemical_reaction/GpqWlKrz">chemical reactions</a>, <a href="/facts/Samarium%25E2%2580%2593neodymium_dating/TaRx8jYl">radioactive dating</a> and <a href="/facts/X-ray_laser/ugyCKgdV">X-ray lasers</a>. Samarium(II) iodide, in particular, is a common <a href="/facts/Reducing_agent/CtfSGVXC">reducing agent</a> in <a href="/facts/Chemical_synthesis/3KXsVVwC">chemical synthesis</a>.
Samarium has no biological role; some samarium salts are slightly toxic.

Samarium open-in-new

Samarium