Writers: D. Melo; F.T.G. Vieira; T.C.C. Costa; L.E.B. Soledade; C.A. Paskocimas; D.M.A. Melo; E. Longo; E.P. Marinho; A.G. Souza; I.M.G. Santos
Keywords: Polymeric precursor method; Perovskite; Black pigment; Lanthanum; Cobaltite; Solid solution
Abstract: In this work La1−xCaxCoO3 (x = 0–0.4) pigments were synthesized by the polymeric precursor method with heat treatments at 700, 800 and 900 °C for 4 h. The powders were characterized by colorimetry, UV–vis spectroscopy and powder X-ray diffraction (XRD). The X-ray diffraction patterns showed the presence of a single phase perovskite, changing its structure from rhombohedral to cubic, when calcium was added to the lattice. All of the pigments had a black colour with a strong absorption over the whole of the visible spectrum as a consequence of the different oxidation states of cobalt and the high short-range disorder. The substitution of Ca2+ for La3+ did not influence the pigment colour but decreased its final cost.
See PDF: Lanthanum cobaltite black pigments with perovskite structure
DOI: 10.1016/j.dyepig.2013.03.012
