Pink and blue materials with olivine solid solutions and pink diopside solid solutions: towards more sustainable pigments

• DOI: 10.1063/4.0000646
• Publication Date: 2025-04-10T18:40:53Z
• Authors: Santiago Garcia-G...; M. A. Tena; Mohammed S. M. Ab...; Camino Trobajo; José R. García

In this study, the evolution of the color with composition and temperature will be explained by the structural characterization of MgCoxNi1-xSiO4(1), Na2CoxNi1-xSi4O10 and Na2Mg1-xCoxSiO4 (0.0 ≤ x ≤ 1.0) in which olivine structure is developedand CaMg0.5CoxNi0.5-xSi2O6 (0 ≤ x ≤ 0.5) with diopside structure(2) fired materials. These compositions were prepared via the chemical co-precipitation method to minimise the toxic and expensive amounts of cobalt and nickel. The colour of these materials are pink from MgCoxNi1-xSiO4 and CaMg0.5CoxNi0.5-xSi2O6 solid solutions or blue from Na2CoxNi1-xSi4O10 and Na2Mg1-xCoxSiO4 compositions. The observed colour of the glazed tiles is due to the Ni(II)/Co(II) ratio as solid solutions dissolve in the glazes. A higher amount of Ni(II) and Co(II) is not necessary to develop intense green and blue colorations. The Co(II) amount is 56.14 %-weight in Co2SiO4, 33.7 %-weight in MgCoSiO4, 29,9 %-weight in Na2CoSiO4, 15.5 %-weight in Na2CoSi4O10, 12.6 %-weight in CaMg0.5Co0.5Si2O6 and 7.0 %-weight in Na2Mg0.8Co0.2SiO4. These solid solutions can be used as ceramic dyes when they are dissolved in glazes and the colour in enamelled samples is depending on x. Intense green (higest Ni(II) amounts) and/or blue colorations are developed when these pigments are dissolved in the commercial glaze.