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Zinc sulfide
Identifiers
CAS number 1314-98-3 Yes check.svgY
PubChem 14821
RTECS number ZH5400000
Properties
Molecular formula ZnS
Molar mass 97.474 g/mol
Density 4.090 g/cm3
Melting point

1185 °C (sublim)

Solubility in water negligible
Band gap 3.54 eV (cubic, 300 K)
3.91 eV (hexagonal, 300 K)
Structure
Crystal structure see text
Coordination
geometry
Tetrahedral (Zn2+)
Tetrahedral (S2−)
Thermochemistry
Std enthalpy of
formation
ΔfHo298
−204.6 kJ/mol
Hazards
MSDS ICSC 1627
EU Index Not listed
NFPA 704
NFPA 704.svg
0
1
0
Flash point non-flammable
Related compounds
Other anions Zinc oxide
Zinc selenide
Zinc telluride
Other cations Cadmium sulfide
Mercury sulfide
 Yes check.svgY (what is this?)  (verify)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Zinc sulfide (or zinc sulphide) is a chemical compound with the formula ZnS. Zinc sulfide is a white- to yellow-colored powder or crystal. It is typically encountered in the more stable cubic form, known also as zinc blende or sphalerite.[1] The hexagonal form is also known both as a synthetic material and as the mineral wurtzite.[1] A tetragonal form is also known as very rare mineral polhemusite (Zn,Hg)S. Both sphalerite and wurtzite are intrinsic, wide-bandgap semiconductors. The cubic form has a band gap of 3.54 eV at 300 K whereas the hexagonal form has a band gap of 3.91 eV. The transition from the sphalerite form to the wurtzite form occurs at around 1020 ºC.

Contents

Applications

The first time the phosphorescence of ZnS was observed by the French chemist Théodore Sidot in 1866. His findings were presented by the renown chemist A. E. Becquerel who was involved in the research on luminescence and phosphorescence.[2]

ZnS was used by Ernest Rutherford and others in the early years of nuclear physics as a scintillation detector, because it emits light on excitation by x-rays or electron beam, making it useful for x-ray screens and cathode ray tubes.[3] It also exhibits phosphorescence due to impurities on illumination with blue or ultraviolet light.

Zinc sulfide, with addition of few ppm of suitable activator, is used as phosphor in many applications, from cathode ray tubes through x-ray screens to glow in the dark products. When silver is used as activator, the resulting color is bright blue, with maximum at 450 nm. Manganese yields an orange-red color at around 590 nm. Copper provides long glow time and the familiar glow-in-the-dark greenish color. Copper doped zinc sulfide (ZnS+Cu) is used also in electroluminescent panels.

Zinc sulfide is also used as an infrared optical material, transmitting from visible wavelengths to over 12 micrometres. It can be used planar as an optical window or shaped into a lens. It is made as microcrystalline sheets by the synthesis from hydrogen sulfide gas and zinc vapour and sold as FLIR (Forward Looking IR) grade ZnS a pale milky yellow visibly opaque form. This material when hot isostatically pressed (HIPed) can be converted to a water-clear form known as Cleartran (trademark). Early commercial forms were marketed as Irtran-2 but this designation is now obsolete.

It can be doped as both n-type semiconductor and p-type semiconductor, which is unusual for the II-VI semiconductors. ZnS is a covalently bonded solid.

Production in lab

It is easily produced by mixing an amount of zinc and sulfur and then igniting it. The result (after cooling) is zinc sulfide.
Zinc sulfide is insoluble in water and solutions containing Zn2+ readily precipitate ZnS in the presence of sulfide ions (e.g., from H2S).

Zn2+ + S2− → ZnS

This has formed the basis of a gravimetric analysis for zinc.[4]

References

  1. ^ a b Wells, A. F. (1984), Structural Inorganic Chemistry (5th ed.), Oxford: Clarendon Press, ISBN 0-19-855370-6 
  2. ^ Sidot, T. (1866). ". Sur les propriétés de la blende hexagonale". Compt. rend. 63.: 188–189. http://gallica.bnf.fr/ark:/12148/bpt6k30204.image.f188.langFR. 
  3. ^ Greenwood, Norman N.; Earnshaw, A. (1984), Chemistry of the Elements, Oxford: Pergamon, p. 1405, ISBN 0-08-022057-6 
  4. ^ Mendham, J.; Denney, R. C.; Barnes, J. D.; Thomas, M.J.K.; Denney, R. C.; Thomas, M. J. K. (2000), Vogel's Quantitative Chemical Analysis (6th ed.), New York: Prentice Hall, ISBN 0-582-22628-7 

External links

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Simple English

Zinc sulfide is a chemical compound. Its chemical formula is ZnS. It contains zinc and sulfide ions.

Contents

Properties

Zinc sulfide is white when pure. It does not dissolve in water. It can burn at a high temperature to make sulfur dioxide and zinc oxide. It reacts with strong acids to make hydrogen sulfide.

Preparation

Zinc sulfide can be made by igniting a mixture of powdered zinc and sulfur. Another way of making it is to react hydrogen sulfide with a zinc compound.

Uses

Zinc sulfide is used to convert ultraviolet light to visible light. It can be doped with copper to make it glow in the dark.

See also


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