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 MgTiO and ZnTiO, respectively gives one family of cobalt greens. These materials adopt the spinel structure. Rinman's green. 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 ZnCoO 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. Cobalt green has been tested for use in "spintronic" devices. Cobalt green is attractive in this application because it is magnetic at room temperature. Cobalt green Cobalt