The Color Sift of Cerium Molybdenum Sheelite by Substituting Bi3+ or W6+ Ion

We prepared chemical compounds whose Ce3+ ions are replaced with Bi3+ ions at a certain rate in LiCeMo2O8, NaCeMo2O8, Ca0.5CeMo2O8, and Sr0.5CeMo2O8 that have the sheelite crystal structure, and the change of the hue of these materials was investigated. In addition, the cause of Ce3+ ion color development in the sheelite structure was studied based on the result of substituting Bi3+ ions for Ce3+ ions and change of the hue of the compounds whose Mo6+ ions are replaced with W6+ ions. The result revealed that the absorption edge shifted to the longer wavelength side as the amount of the replaced Bi3+ ions increased, and the hue of the product changed from yellow to reddish yellow. The changes in the chemical bonding nature of the crystal were found to give a great impact on the color development of the Ce3+ ion. Although the Ce3+ ion takes on the yellow hue in the sheelite crystal structure, its absorption edge can be shifted freely by generating the substitutional solid solution of metal ions with different electronegativity.