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Cobalt green

From Wikipedia, the free encyclopedia
Cobalt green
Names
Other names
cinnabar green, turquoise green, Rinman's green, Rinmann's green, zinc green
Identifiers
Properties
Zn1−xCoxO
Insoluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Cobalt green is an ambiguous term for either of two families of green inorganic pigments. Both are obtained by doping cobalt(II) oxide into colorless host oxides.

Spinel-based cobalt green

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Doping Co(II) into Mg(II) and Zn(II) sites of Mg2TiO4 and Zn2TiO4, respectively gives one family of cobalt greens. These materials adopt the spinel structure.[1]

Rinman's green

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Rinman's green, also referred to as Rinmann's green, is obtained by doping cobalt(II) oxide into zinc oxide. Sven Rinman, a Swedish chemist, discovered this compound in 1780. Zinc oxide–derived pigments have been used in many industries and processes. It is rarely used because it is a weak chromophore and relatively expensive compared to chromium(III) oxide.

The structure and color of compositions Zn1−xCoxO depends on the value of x. For x ≤ 0.3, the material adopts the Wurzite structure (of ZnO) and is intensely green. For x ≥ 0.7, the material has the sodium chloride structure (of CoO) and is pink. Intermediate values of x give a mixture of the two phases.[2]

Cobalt green has been tested for use in "spintronic" devices. Cobalt green is attractive in this application because it is magnetic at room temperature.[3]

See also

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References

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  1. ^ Völz, Hans G. et al. "Pigments, Inorganic" in Ullmann's Encyclopedia of Industrial Chemistry, 2006 Wiley-VCH, Weinheim. doi:10.1002/14356007.a20_243.pub2.
  2. ^ F. Wagenknecht, and R. Juza "Rinmann's Green" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1092.
  3. ^ Djerdj, Igor; Jaglicic, Zvonko; Arcon, Denis; Niederberger, Markus (2010). "Co-Doped ZnO nanoparticles: Minireview". Nanoscale. 2 (7): 1096–1104. Bibcode:2010Nanos...2.1096D. doi:10.1039/c0nr00148a. PMID 20648333.
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