A comparative study of the influence of mineralisers on the properties of CoZr4(PO4)6-based pigments

Tailoring the Chemical Composition of LiMPO4 (M = Mg, Co, Ni) Orthophosphates To Design New Inorganic Pigments from Magenta to Yellow Hue

“…Here it can be defined, that a magenta is a pigment with L*a*b* parameters such as the luminosity L* is in the range 50-70, the red/blue ratio a*/b* about 3/-2 with the highest a* as possible (best organic pigment for inkjet can exhibit a* over 60). As far as we know, the colorimetric parameters of these three cobalt-phosphates are not directly compared and discussed in literature, but independently studied [33], [39], [40]. Especially, LiMPO4 have been investigating for their interesting pigment properties because a wide range of colors can be obtained when they are doped with one or more different transition metals (V, Cr, Mn, Fe, Co, Ni, Cu) [28], [41].…”

“…As far as we know, the colorimetric parameters of these three cobalt phosphates have not been directly compared and discussed in the literature but independently studied. 33,39,40 Especially, LiMPO 4 have been investigated for their interesting pigment properties because a wide range of colors can be obtained when they are doped with one or more different transition metals (V, Cr, Mn, Fe, Co, Ni, and Cu). 28,41 Solid-state preparations were carried out using the same synthesis conditions, except for the cooling ramp of the thermal treatment, which was varied for the preparation of β-NaCoPO For the NaCoPO 4 composition, two allotropic varieties can be obtained depending on the cooling rate: the α form corresponding to the olivine structure with the Pnma space group, i.e., isostructural to LiCoPO 4 , is obtained, while a slow cooling ramp is used; the β form with the P2 1 /n space group is obtained, while a rapid quenching is performed.…”

“…Magenta pigments are mentioned in borates series [28], whereas most of inorganic pigments detailed in literature are pink pigments, relatively far, in term of colorimetric parameters, from a magenta hue [29]- [31]. Besides the purple colour of Co3(PO4)2, new purple-blue ceramic pigments corresponding to CoZr4(PO4)6 and CoKZr2(PO4)3 phosphates were recently investigated [32], [33], [34]. These frameworks derive from the NASICON-type structure [10] NaZr2(PO4)3 where Na + ions occupy a regular octahedral site.…”

“…Magenta and yellow inorganic pigments have not been largely investigated with the objective to disperse them in organic media. Magenta pigments are mentioned in borate series, whereas most inorganic pigments detailed in the literature are pink pigments, relatively far, in terms of colorimetric parameters, from a magenta hue. − Besides the purple color of Co 3 (PO 4 ) 2 , new purple-blue ceramic pigments corresponding to CoZr 4 (PO 4 ) 6 and CoKZr 2 (PO 4 ) 3 phosphates were recently investigated. − These frameworks derive from the NASICON-type structure NaZr 2 (PO 4 ) 3 where Na + ions occupy a regular octahedral site. These works showed that the Co 2+ ion in octahedral coordination stabilized in the phosphate network, leading to purple coloration.…”

Effect of sol–gel method on colour properties of the classical cobalt olivine (Co2SiO4) ceramic pigment

“…Regarding .60), which should be accompanied by a slight decrease of colour saturation. Thus, since good colour saturation depends generally on improved crystallinity and/or chemical homogeneity of the pigments [18], these observations suggest that the decrease in lightness as well as the increase in absorbance intensity (figure 4) when passing from CO1 to CO4 sample is due to the increased amount of residual CoO in the same direction. Therefore, method-mineralizer combinations may be classified according to their ascending contribution to the formation of Co olivine as follows: (reflux-KCl) < (hydrothermal-KCl) < (reflux-NaCl) < (hydrothermal-NaCl).…”