Ammonia-free synthesis and color tuning of oxynitride perovskite SrTaO2N-SrTiO3 solid solution by using alkoxide-derived Ta-Ti binary oxide gel precursors

Solid solutions of strontium-tantalum oxynitride perovskite (SrTaO2N) and strontium-titanium oxide perovskite (SrTiO3) were prepared as possible candidates for novel inorganic pigments. The use of Ta-Ti binary oxide gel, which was obtained by the sol-gel method, was conducive to the development of single-phase solid solutions with a homogeneous atomic distribution. In addition, the use of urea as a nitriding agent availed to eliminate harmful ammonia gas during the synthesis. The color of solid solution depends on the band gap and Ti reduction state, which changes with Ti content. As a result, various chromatic colors, i.e., orange to yellow-green, were obtained from solid solutions. The solid solutions retained their color even after thermal and chemical resistance examinations. Because toxic substances were eliminated from the products and preparation process, the solid solutions show potentials to be applied as environmentally-friendly pigments. [GRAPHICS] .

Automated summary

The use of Ta-Ti binary oxide gel helps in developing single-phase solid solutions with homogeneous atomic distribution; utilizing urea as a nitriding agent eliminates harmful ammonia gas; the color of solid solutions depends on band gap and Ti reduction state, resulting in various chromatic colors.