Ni-free, black ceramic pigments based on Co—Cr—Fe—Mn spinels: A reappraisal of crystal structure, colour and technological behaviour

Investigation of the anticorrosion efficiency of ferrites Mg1−xZnxFe2O4 with different particle morphology and chemical composition in epoxy-ester resin-based coatings

“…The crystal structure of spinel pigments derives from the mineral spinel (MgAl 2 O 4 ). Three oxidation state combinations are conceivable for charge compensation in oxides with the general formula AB 2 [13,14]. The factors determining which atom combinations can form a spinel structure include the formal charge of the cation, the relative size of the cations [15].…”

Synthesis and coloring performance of Ni-geikielite (Ni,Mg)TiO3 yellow pigments: Effect of temperature, Ni-doping and synthesis method

“…In most cases, however, a much better understanding of the crucial role played by crystal chemical aspects is still needed to modulate or improve the coloring performance of already known or even new ceramic pigments. By an accurate knowledge and control of chromophore metal-oxygen distances [3], local environment distortions [6][7][8], cation order-disorder phenomena [9,10], structural relaxation or covalence effects [11] etc., the band gap energies [12][13][14], metal-ligand charge transfers [8] and crystal field intensities and energies on chromophore ions in a particular coordination environment can be tuned [11,12,15], and this is of paramount importance to optimize the coloring properties or to discover new ceramic pigments [16].…”

“…Taking into account that Ni is a rather scarce and toxic element [42], relatively low amounts of Ni (10, 20 and 40 mol%) were employed, similarly to previous Ni-minimization studies performed in other ceramic pigments [16,43,44]. In order to overcome the typical problems inherent to traditional solid-state preparation methods (high reaction temperatures, uncontrolled morphologies, coarser particles, lack of chemical homogeneity, etc.…”

Micronizing ceramic pigments for inkjet printing: Part I. Grindability and particle size distribution

“…In particular, vanadium-doped turquoise zircon (ZrSiO 4 :V) [30,31], a black pigment with composition in the Co-Cr-Fe-Mn-Ni system [32,33] and an orange-yellow pigment doped with chromium and antimony (TiO 2 :Cr,Sb) were considered [34,35].…”