What is Samarium?

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To explain what Samarium is, it is a chemical element which is represented by the symbol of the Sm element in the periodic table and the atomic number of Samarium is 62. In the year 1879, Samarium was discovered by Paul Emile Lecoq de Boisbaudran. It is a silvery, hard type of metal which oxidizes slowly in the air. It is a member of the lanthanide series which makes Samarium assuming oxidation state +3. Monoxide SmO, monochalcogenides Sms, SmSe and SmTe and samarium(II) iodide are generally compounds of Samarium. There is no significant biological role which can be found in Samarium, but only Samarium is slightly a toxic element. 

Uses Of Samarium 

What is Samarium used for can be explained as:

  • Samarium-Cobalt magnets which have a very high permanent magnetization is one of the most critical applications of Samarium. These magnets can be seen used in headphones, small motors and musical instruments like guitars.

  • In the manufacturing of solar-powered electric aircraft, this element can be seen.

  • In the making of special infrared absorbing glass and cores of carbon arc lamp electrodes, are considered as uses of Samarium.

  • It also acts as a catalyst in the ethanol dehydration process as well as uses of Samarium can be making new permanent magnets.

Properties Of Samarium 

Physical Properties Of Samarium 

Samarium is a rare earth metal having a hardness and thickness like those of zinc. With a boiling point of 1794 °C, Samarium is the third most volatile lanthanide after ytterbium and europium; this property encourages detachment of Samarium from the mineral ore. At surrounding conditions, Samarium typically accepts a rhombohedral structure (α form). After warming to 731 °C, its crystal symmetry changes into hexagonally close-packed (hcp), anyway the progress temperature relies upon the metal immaculateness. Further warming to 922 °C changes the metal into a body-centred cubic (bcc) stage. Warming to 300 °C joined with pressure to 40 kbar brings about a twofold hexagonally close-packed structure (dhcp). Samarium electron configuration is [Xe] 4f66s2. and Samarium atomic mass is 150.36 u.

Chemical Properties Of Samarium 

Newly prepared Samarium has a silvery radiance. In the air, it gradually oxidized at room temperature and suddenly ignites at 150 °C. In any point, when put away under mineral oil, samarium bit by bit oxidizes and builds up a greyish-yellow powder of the oxide-hydroxide blend at the surface. The metallic appearance of an example can be safeguarded via fixing it under inert gas, for example, argon. 

Samarium is very electropositive and responds gradually with cold water and rapidly with hot water to shape samarium hydroxide: 

2Sm(OH)3 (aq) + 3H2 (g) → 2Sm (s) + 6H2O (l) 

Samarium disintegrates promptly in dilute sulfuric acid to shape solutions containing the yellow to light green Sm(III) ions, which exist as [Sm(OH2)9]3+ complexes: 

2Sm (s) + 3 H2SO4 (aq) → 2 Sm3+ (aq) + 3 S(aq) + 3 H2 (g) 

One of the few lanthanides is samarium that exhibit the +2 oxidation state. The Sm2+ particles are dark red in fluid solution.

Compounds Of Samarium 


Sesquioxide Sm2O3 is the most stable oxide of the Sm element. It exists in several crystalline phases, as many other samarium compounds. The trigonal form is obtained by slow cooling of the melt. 


Sm element forms trivalent sulfide, telluride and selenide. Divalent Chalcogenides SmS, SmSe and SmTe with cubic rock salt crustal structure are also known. By converting from semiconducting to metallic state at room temperature upon application of pressure is what Chalcogenides of the Sm element are known for.


Sm element reacts with all the halogens, forming trihalides.

2 Sm (s) + 3 X2 (g) → 2 SmX3 (s) (X = F, Cl, Br or I)

The further reduction with Samarium, lithium or sodium metals at elevated temperatures (about 700–900 °C) yields dihalides. The reduction also produces numerous non-stoichiometric samarium halides with crystal structure adding with the dihalides, such as Sm3F7, Sm14F33, Sm27F64, Sm11Br24, Sm5Br11 and Sm6Br13.

Solved Examples 

  1. About 1016 years is taken for just half the samarium-149 in nature to decay by alpha-particle emission. Explain the decay equation and isotope that is produced by the reaction?

For samarium-149, the atomic number of Samarium is equal to 62 and a mass number is equal to 149. This means 

149=b+4→ mass number conservation

62=a+2→ change conservation

You will get



The element that has an atomic number equal to 60 is neodymium, Nd.

Neodymium-145 will be produced by the alpha decay of samarium-149 and an alpha particle.

62149Sm ---> 60145Nd + 24He

Fun Fact 

  1. Uses of Samarium have no biological role, and it is not that toxic. It is observed that some soluble salts are mildly toxic but cannot affect the human life.

  2. Samarium is said to be the hardest member of the cerium group of earth metals.

  3. Samarium has a bright silver metallic lustre. 

  4. The origin of the name of Samarium is from smarskite, which is a mineral.

FAQ (Frequently Asked Questions)

1. Explain the History and Uses of Samarium?

Samarium was watched spectroscopically by Jean Charles Galissard de Marignac, a Swiss scientist, in a material known as dydimia in 1853. Paul-Émile Lecoq de Boisbaudran, a French scientist, was the first to seclude Samarium from the mineral samarskite ((Y, Ce, U, Fe)3(Nb, Ta, Ti)5O16) in 1879. Samarium nowadays is obtained through an ion exchange process from monazite sand, a material rich in earth components that contain as much as 2.8% samarium. 

Samarium is one of the uncommon earth components used to make carbon circular segment lights which are utilized in the motion picture industry for studio lighting and projector lights. 

2. Where Can We Commonly Have Found Samarium?

The fifth most abundant of the rare elements can be said as Samarium and is almost four times as common as tin. It is not found free in nature, but is contained in several minerals, including monazite, bastnasite and samarskite. Samarium has ores which are found in India, Australia, USA, China, Brazil and Sri Lanka. World production of samarium oxide is about 700 tonnes per year and world-wide reserves are estimated to be around 2 million tonnes. The Samarium electron configuration is [Xe] 4f6 6s2. and Samarium atomic mass is 150.36 u. The major commercial application is Samarium–cobalt magnets where Samarium is in.