Samarium(III) sulfide ( Sm₂ S₃) is a chemical compound of the rare earth element samarium, and

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

. In this compound samarium is in the +3 oxidation state, and sulfur is an anion in the −2 state.

Production

One way to make Samarium(III) sulfide is to heat samarium metal with sulfur. Another way to make a thin film is to alternatively soak in samarium(III) chloride tartaric acid complex, and sodium thiosulfate.

Properties

The low temperature α form crystallises in the orthorhombic crystal system. The unit cell has dimensions a=7.376, b=3.9622 c=15.352 Å with volume 448.7 Å₃. There are four of the formula in each unit cell (Sm₈S₁₂). The density comes out to 5.88 kg/liter. There are two kinds of samarium coordination in the solid, one is eight coordinated with sulfur surrounding in a bicapped

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. The other is a sevenfold capped distorted octahedral arrangement. This structure is similar to other light rare-earth element sulfides. Samarium(III) sulfide is a semiconductor with a band gap of 1.7 eV. As a thin film on high area electrodes, it is under investigation as a

super capacitor A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor, with a capacitance value much higher than other capacitors but with lower voltage limits. It bridges the gap between electrolytic capacitors and rechargeable ba ...

dielectric, with

specific capacitance Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final ...

s of up to 360

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s per gram.

Related samarium sulfides include the monosulfide SmS and the mixed valent Sm₃S₄ which are also semiconductors. KSm₂CuS₆ is a layered quaternary sulfide.

References

{{Sulfides Sesquisulfides Samarium(III) compounds