Improvement of chroma of tantalum(V) nitride pigment by low-temperature oxidation treatment

Abstract

Tantalum(V) nitride (Ta₃N₅) pigment have attracted considerable attention as an alternative candidate for the colors of the cadmium base. The improvement of chroma of the pigment is necessary to raise the charm as the color. In this study, the Ta₃N₅ pigment was prepared by heat-treatment for mixed powders of Ta(V) oxide, aluminum nitride and potassium fluoride in nitrogen gas which kept supplied during the synthesis until it got cooled to room temperature. The pigment prepared in such completely inert atmosphere had slightly dull color. However, the chroma of the pigment was largely improved by a subsequent low-temperature oxidation treatment.