Ceramic pigments based on chromium doped alkaline earth titanates

Abstract

In this paper M(Ti1−xCrx)O3 with M=Mg, Ca, Sr, Ba and x=0.01, 0.03, 0.05, 0.1 compositions have been prepared by solid state reaction in order to analyze their reactivity, structure, limit of solid solution, stability and pigmenting properties in conventional ceramic glazes. Cr–MgTiO3 crystallizes magnesium ilmenite MgTiO3 (SG=R-3) with residual MgCr2O4 spinel that inhibits the Cr entrance in solid solution and do not show pigmenting properties. Cr–CaTiO3 crystallizes orthorhombic perovskite (SG=Pbnm) pink solid solutions associated to Cr4+–Ti4+ substitutions which above x=0.03 unstabilizes in glazes and produce light green shades. Cr–SrTiO3 crystallizes ideal cubic perovskite (SG=Pm3m) pink solid solutions that unstabilizes in glazes above x=0.01. Finally Cr–BaTiO3 crystallizes tetragonal perovskite (SG=P4mn) with residual peaks of BaCrO4 at x=0.1 showing pink solid solutions until x=0.05 that unstabilizes in glazes above x=0.03. All powders show aggregates (between 2–10 μm of size) of fine particles (between 200–1000 nm).