Cobalt green
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
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
Template:Chembox 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 Wurtzite 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
References
- ↑ Völz, Hans G. et al. "Pigments, Inorganic" in Ullmann's Encyclopedia of Industrial Chemistry, 2006 Wiley-VCH, Weinheim. Script error: No such module "doi"..
- ↑ 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.
- ↑ Script error: No such module "Citation/CS1".