Characteristics reproducibility of (Fe, Co)(Cr, Al)2O4 pigments obtained by solution combustion synthesis

Synthesis reproducibility of mixed spinels Fe1−ΨCoΨCr2−2ΨAl2ΨO4 (0≤Ψ≤1), obtained by Solution Combustion Synthesis using urea as fuel, has been studied. Pigments with spinel structure Fd-3m have been obtained for all the compositional range analysed. Characteristics such as crystallinity, cell parameter, crystal size and specific surface area show a noticeable dependence with Ψ, but some of them present a low reproducibility, indicating a pronounced dependency with process conditions in each batch.Colouring power of synthesized pigments is highly significant, so they can be directly integrated in ceramic glasses without introducing a second thermal treatment. However, the generated colour also suffers from a limited reproducibility.