Synthesis of Bi₂O₃–ZrO₂ solid solutions for environment-friendly orange pigments

Abstract

Bi_2−xZr_3x/4O₃ solid solutions were synthesized by conventional ceramic method and their color properties were investigated as environment-friendly inorganic orange pigments. Single phased Bi_2−xZr_3x/4O₃ solid solutions with tetragonal crystal structure are formed in the range of 0.3 ≤ x ≤ 0.5 compositions. Brilliant orange color powders were obtained for x = 0.5 composition heated at 800°C, which had color parameters (L*, a*, b*) of L* = 68, a* = 34, and b* = 69. The color of x = 0.5 samples is comparable to that of orange color specified in Japanese Industrial Standards (JIS) for a traffic paint. Since Bi_2−xZr_3x/4O₃ solid solutions are composed of nontoxic elements, it should be an alternative candidates to conventional PbCrO₄-based pigments for traffic paint.