Niobium disulfide

Last updated • a couple of secsFrom Wikipedia, The Free Encyclopedia
Niobium disulfide
NbS2 film.jpg
NbS2 exfoliated layer
NbS2.png
NbS2 structure
Names
IUPAC name
niobium(IV) sulfde, niobium disulfde
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • Key: VRSMQRZDMZDXAU-UHFFFAOYSA-N
  • InChI=1S/Nb.2S
  • S=[Nb]=S
Properties
NbS2
Molar mass 157.038 g/mol [1]
AppearanceBlack crystals [1]
Density 4.4 g/cm3 [1]
+120·10−6 cm3/mol [2]
Structure [3]
Trigonal, hR9, No. 160
R3m
a = 0.333 nm, b = 0.333 nm, c = 1.78 nm
α = 90°, β = 90°, γ = 120°
3
Related compounds
Other anions
Niobium diselenide, Niobium ditelluride
Other cations
Vanadium disulfide, Tantalum disulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Niobium disulfide is the chemical compound with the formula NbS2. It is a black layered solid that can be exfoliated into ultrathin grayish sheets similar to other transition metal dichalcogenides. These layers exhibit superconductivity, where the transition temperature increases from ca. 2 to 6 K with the layer thickness increasing from 6 to 12 nm, and then saturates with thickness. [4]

Related Research Articles

<span class="mw-page-title-main">Niobium</span> Chemical element, symbol Nb and atomic number 41

Niobium is a chemical element; it has symbol Nb and atomic number 41. It is a light grey, crystalline, and ductile transition metal. Pure niobium has a Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite, hence the former name "columbium". Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish.

<span class="mw-page-title-main">Superconductivity</span> Electrical conductivity with exactly zero resistance

Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered, even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.

<span class="mw-page-title-main">Tantalum</span> Chemical element, symbol Ta and atomic number 73

Tantalum is a chemical element; it has symbol Ta and atomic number 73. Previously known as tantalium, it is named after Tantalus, a figure in Greek mythology. Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as components of strong high-melting-point alloys. It is a group 5 element, along with vanadium and niobium, and it always occurs in geologic sources together with the chemically similar niobium, mainly in the mineral groups tantalite, columbite and coltan.

<span class="mw-page-title-main">Molybdenum disulfide</span> Chemical compound

Molybdenum disulfide is an inorganic compound composed of molybdenum and sulfur. Its chemical formula is MoS
2
.

<span class="mw-page-title-main">Yttrium barium copper oxide</span> Chemical compound

Yttrium barium copper oxide (YBCO) is a family of crystalline chemical compounds that display high-temperature superconductivity; it includes the first material ever discovered to become superconducting above the boiling point of liquid nitrogen [77 K ] at about 93 K.

<span class="mw-page-title-main">History of superconductivity</span>

Superconductivity is the phenomenon of certain materials exhibiting zero electrical resistance and the expulsion of magnetic fields below a characteristic temperature. The history of superconductivity began with Dutch physicist Heike Kamerlingh Onnes's discovery of superconductivity in mercury in 1911. Since then, many other superconducting materials have been discovered and the theory of superconductivity has been developed. These subjects remain active areas of study in the field of condensed matter physics.

<span class="mw-page-title-main">Niobium–tin</span> Superconducting intermetallic compound

Niobium–tin is an intermetallic compound of niobium (Nb) and tin (Sn), used industrially as a type-II superconductor. This intermetallic compound has a simple structure: A3B. It is more expensive than niobium–titanium (NbTi), but remains superconducting up to a magnetic flux density of 30 teslas [T] (300,000 G), compared to a limit of roughly 15 T for NbTi.

<span class="mw-page-title-main">A15 phases</span>

The A15 phases (also known as β-W or Cr3Si structure types) are series of intermetallic compounds with the chemical formula A3B (where A is a transition metal and B can be any element) and a specific structure. The A15 phase is also one of the members in the Frank–Kasper phases family. Many of these compounds have superconductivity at around 20 K (−253 °C; −424 °F), which is comparatively high, and remain superconductive in magnetic fields of tens of teslas (hundreds of kilogauss). This kind of superconductivity (Type-II superconductivity) is an important area of study as it has several practical applications.

<span class="mw-page-title-main">Type-II superconductor</span> Superconductor characterized by the formation of magnetic vortices in an applied magnetic field

In superconductivity, a type-II superconductor is a superconductor that exhibits an intermediate phase of mixed ordinary and superconducting properties at intermediate temperature and fields above the superconducting phases. It also features the formation of magnetic field vortices with an applied external magnetic field. This occurs above a certain critical field strength Hc1. The vortex density increases with increasing field strength. At a higher critical field Hc2, superconductivity is destroyed. Type-II superconductors do not exhibit a complete Meissner effect.

<span class="mw-page-title-main">Tantalum(IV) sulfide</span> Chemical compound

Tantalum(IV) sulfide is an inorganic compound with the formula TaS2. It is a layered compound with three-coordinate sulfide centres and trigonal prismatic or octahedral metal centres. It is structurally similar to molybdenum disulfide MoS2, and numerous other transition metal dichalcogenides. Tantalum disulfide has three polymorphs 1T-TaS2, 2H-TaS2, and 3R-TaS2, representing trigonal, hexagonal, and rhombohedral respectively.

<span class="mw-page-title-main">Niobium monoxide</span> Chemical compound

Niobium monoxide is the inorganic compound with the formula NbO. It is a grey solid with metallic conductivity.

<span class="mw-page-title-main">Superconducting wire</span> Wires exhibiting zero resistance

Superconducting wires are electrical wires made of superconductive material. When cooled below their transition temperatures, they have zero electrical resistance. Most commonly, conventional superconductors such as niobium–titanium are used, but high-temperature superconductors such as YBCO are entering the market.

<span class="mw-page-title-main">Niobium triselenide</span> Chemical compound

Niobium triselenide is an inorganic compound belonging to the class of transition metal trichalcogenides. It has the formula NbSe3. It was the first reported example of one-dimensional compound to exhibit the phenomenon of sliding charge density waves. Due to its many studies and exhibited phenomena in quantum mechanics, niobium triselenide has become the model system for quasi-1-D charge density waves.

<span class="mw-page-title-main">Molybdenum diselenide</span> Chemical compound

Molybdenum diselenide is an inorganic compound of molybdenum and selenium. Its structure is similar to that of MoS
2
. Compounds of this category are known as transition metal dichalcogenides, abbreviated TMDCs. These compounds, as the name suggests, are made up of a transition metals and elements of group 16 on the periodic table of the elements. Compared to MoS
2
, MoSe
2
exhibits higher electrical conductivity.

<span class="mw-page-title-main">Tungsten diselenide</span> Chemical compound

Tungsten diselenide is an inorganic compound with the formula WSe2. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide. The tungsten atoms are covalently bonded to six selenium ligands in a trigonal prismatic coordination sphere while each selenium is bonded to three tungsten atoms in a pyramidal geometry. The tungsten–selenium bond has a length of 0.2526 nm, and the distance between selenium atoms is 0.334 nm. It is a well studied example of a layered material. The layers stack together via van der Waals interactions. WSe2 is a very stable semiconductor in the group-VI transition metal dichalcogenides.

<span class="mw-page-title-main">Transition metal dichalcogenide monolayers</span> Thin semiconductors

Transition-metal dichalcogenide (TMD or TMDC) monolayers are atomically thin semiconductors of the type MX2, with M a transition-metal atom (Mo, W, etc.) and X a chalcogen atom (S, Se, or Te). One layer of M atoms is sandwiched between two layers of X atoms. They are part of the large family of so-called 2D materials, named so to emphasize their extraordinary thinness. For example, a MoS2 monolayer is only 6.5 Å thick. The key feature of these materials is the interaction of large atoms in the 2D structure as compared with first-row transition-metal dichalcogenides, e.g., WTe2 exhibits anomalous giant magnetoresistance and superconductivity.

<span class="mw-page-title-main">Niobium diselenide</span> Chemical compound

Niobium diselenide or niobium(IV) selenide is a layered transition metal dichalcogenide with formula NbSe2. Niobium diselenide is a lubricant, and a superconductor at temperatures below 7.2 K that exhibit a charge density wave (CDW). NbSe2 crystallizes in several related forms, and can be mechanically exfoliated into monatomic layers, similar to other transition metal dichalcogenide monolayers. Monolayer NbSe2 exhibits very different properties from the bulk material, such as of Ising superconductivity, quantum metallic state, and strong enhancement of the CDW.

<span class="mw-page-title-main">Hafnium disulfide</span> Chemical compound

Hafnium disulfide is an inorganic compound of hafnium and sulfur. It is a layered dichalcogenide with the chemical formula is HfS2. A few atomic layers of this material can be exfoliated using the standard Scotch Tape technique (see graphene) and used for the fabrication of a field-effect transistor. High-yield synthesis of HfS2 has also been demonstrated using liquid phase exfoliation, resulting in the production of stable few-layer HfS2 flakes. Hafnium disulfide powder can be produced by reacting hydrogen sulfide and hafnium oxides at 500–1300 °C.

<span class="mw-page-title-main">Rhenium disulfide</span> Chemical compound

Rhenium disulfide is an inorganic compound of rhenium and sulfur with the formula ReS2. It has a layered structure where atoms are strongly bonded within each layer. The layers are held together by weak Van der Waals bonds, and can be easily peeled off from the bulk material.

Hafnium compounds are compounds containing the element hafnium (Hf). Due to the lanthanide contraction, the ionic radius of hafnium(IV) (0.78 ångström) is almost the same as that of zirconium(IV) (0.79 angstroms). Consequently, compounds of hafnium(IV) and zirconium(IV) have very similar chemical and physical properties. Hafnium and zirconium tend to occur together in nature and the similarity of their ionic radii makes their chemical separation rather difficult. Hafnium tends to form inorganic compounds in the oxidation state of +4. Halogens react with it to form hafnium tetrahalides. At higher temperatures, hafnium reacts with oxygen, nitrogen, carbon, boron, sulfur, and silicon. Some compounds of hafnium in lower oxidation states are known.

References

  1. 1 2 3 Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. p. 4.76. ISBN   0-8493-0486-5.
  2. Lee, P.A. (6 December 2012). Optical and Electrical Properties. Springer Science & Business Media. p. 446. ISBN   978-94-010-1478-6.
  3. Rajora, O. S.; Curzon, A. E. (1987). "The preparation and X‐ray diffraction study of the layer materials NbSxSe2−x for 0 ≦ x ≦ 2". Physica Status Solidi A. 99: 65–72. doi:10.1002/pssa.2210990108.
  4. Yan, Rusen; Khalsa, Guru; Schaefer, Brian T.; Jarjour, Alexander; Rouvimov, Sergei; Nowack, Katja C.; Xing, Huili G.; Jena, Debdeep (2019). "Evolution of superconductivity in ultrathin NbS2". Applied Physics Express. 12 (2): 023008. arXiv: 1803.06097 . doi:10.7567/1882-0786/aaff89.