Aerosol-derived Mn-doped Al 2O 3 pink pigments prepared in the absence of fluxes

Abstract

A method for the preparation of Mn-doped alumina pink pigments in the absence of fluxes through the pyrolysis of liquid aerosols generated from aluminium(III) nitrate and manganese(II) nitrate aqueous solutions is reported and compared with the traditional ceramic procedure. It was found that the pyrolysis method requires a lower temperature (900 °C) for the development of the corundum phase and the pink colour than that required by the traditional procedure (1300 °C) yielding a more intense colour, as a consequence of the incorporation of a higher amount of Mn in solid solution to the alumina lattice. In addition, the use of the pyrolysis procedure allows the preparation of pigments grains with uniform shape and controlled and reproducible size distribution, not requiring grinding.