|Group||Lanthanides||Melting point||1072 oC, 1962 oF, 1345 K|
|Period||6||Boiling point||1794 oC, 3261 oF, 2067 K|
|Block||f||Density (g cm-3)||7.52|
|Atomic number||62||Relative atomic mass||150.36|
|State at 20°C||Solid||Key isotopes||152Sm|
|Electron configuration||[Xe] 4f66s2||CAS number||7440-19-9|
|ChemSpider ID||22391||ChemSpider is a free chemical structure database|
Samarium is used to dope calcium chloride crystals for use in optical lasers. It is also used in infrared absorbing glass and as a neutron absorber in nuclear reactors. Samarium oxide finds specialised use in glass and ceramics. In common with other lanthanides, samarium is used in carbon arc lighting for studio lighting and projection.
Recently, electrochemical deposition has been used to separate samarium from other lanthanides. A lithium citrate electrolyte is used, and a mercury electrode. Samarium metal can also be produced by reducing the oxide with barium.
|Common oxidation states||3, 2|
|Isotopes||Isotope||Atomic mass||Natural abundance (%)||Half life||Mode of decay|
|147Sm||146.915||14.99||1.06 x 1011 y||a|
|148Sm||147.915||11.24||7 x 1015 y||a|
Samarium was one of the rare earths (aka lanthanoids) which perplexed and puzzled the chemists of the 1800s. Its history began with the discovery of cerium in 1803. This was suspected of harbouring other metals, and in 1839 Carl Mosander claimed to have obtained lanthanum and didymium from it. While he was right about lanthanum, he was wrong about didymium. In 1879, Paul-Émile Lecoq de Boisbaudran extracted didymium from the mineral samarskite. He then made a solution of didymium nitrate and added ammonium hydroxide. He observed that the precipitate which formed came down in two stages. He concentrated his attention on the first precipitate and measured its spectrum which revealed it to be a new element samarium. Samarium itself was eventually to yield other rare-earths: gadolinium in 1886 and europium in 1901.
|Listen to Samarium Podcast|
Chemistry in Its Element - Samarium
You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry
This week, a rare, lustrous element with isotopes that have some unfathomably long half-lives. To tell us more, here's Richard Corfield:
Samarium is a rare earth element that - indirectly - has the distinction of being the first naturally occurring chemical element to be named after a living person. Samarium was isolated from the mineral Samarskite which was discovered near the small town of Miass in the southern Ural mountains in 1847. The mineral was named by the German Mineralogist Heinrich Rose after Vasili Evgrafovich Samarsky-Bykhovets, Chief of Staff of the Russian Corps of Mining Engineers between 1845 and 1861 who had given Rose the ore sample to study.
So get those samarium shares in ASAP. That was science writer Richard Corfield with the geological and technological uses of the element samarium. Now next week, we stick with the lanthanides and hear about an element that likes to play hard to get.
At that time, scientists were using improved techniques such as fractional crystallisation to obtain the individual lanthanides from mixtures. In 1886, Lecoq was the first person to identify dysprosium by separating its oxide from holmium oxide. It took him over 30 goes to do this, so he named the element accordingly, from the Greek word, dysprositos, meaning "hard to get at".
And Simon Cotton will be sharing some of the chemistry, properties and applications of dysprosium in next week's Chemistry in its Element. Until then, I'm Meera Senthilingham and thank you for listening
Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists dot com. There's more information and other episodes of Chemistry in its element on our website at chemistryworld dot org forward slash elements.
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Uses and properties
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Supply risk data
Derived in part from material provided by the British Geological Survey © NERC.
© John Emsley 2012.
Produced by The Naked Scientists.
Periodic Table of Videos
Created by video journalist Brady Haran working with chemists at The University of Nottingham.