Optical properties of Ta(3-x)Zr(x)N(5-x)O(x) semiconductor pigments

Abstract Tantalum zirconium oxynitride phases Ta(3-x)Zr(x)N(5-x)O(x) (0 ≤ x ≤ 0.66) having the Ta3N5 structure and Ta(1-x)Zr(x)N(1−x)O(1+x) (0 ≤ x ≤ 0.28) with the TaON structure have been prepared by solid state-gas syntheses. Oxide precursors have been prepared by a novel sol-gel process variant, using a mixture of acetic acid and acetic anhydride as solvent. The optical properties of the brilliantly coloured pigment quality Ta(3-x)Zr(x)N(5-x)O(x) (0 ≤ x ≤ 0.66) semiconducting oxynitrides have been examined by UV-VIS remission spectroscopy. Their applicability for an industrial scale production and a widespread use as brilliant, lightfast and inert inorganic colouring agents has been investigated. These pigments may be useful for colouring paints, plastics and medium temperature ceramic applications, replacing comtemporary toxic metal containing pigments.