Relationship between Color of Chromium Oxide in Lime Glaze and Chemical Composition of Glaze

摘要

Relationship between color of chromium green glaze fired at l280 deg C under oxidation atmosphere and its chemical composition was successfully analyzed by a newly developed method measuring absorption and scattering coefficients. Sixteen glazes were prepared by adding 0.25 mass percent Cr_2Oa into the base glazes with Segar formulars of 0.3 KNaO, 0.7CaO, xAl_2O_3, y SiO_2 (x=0.35, 0.40,0.45,0.50; y=3.5, 4.0,4.5,5.0). Complicated changes in the apparent color of the glaze were observed because of the occurrence of several elemental changes in the absorption and scattering coefficients. The decrease in the scattering coefficient with increasing A1_2O_3 amount could be related to the amount of a Wollastonite crystalline phase, which had a significant influence on the apparent color of the glaze. Relationship between absorption coefficient and glaze composition could be clearly detected, which indicated a change in chemical state of Cr.