XU Yinan ¹, CHENG Zhipeng ¹, WU Kuangzhen ², LIU Kun ¹, BAO Qifu ¹,YANG Ruiqiang ¹, ZHAO Tiangui ^{1, 2}, ZHOU Jianʼer ¹

(1. Jingdezhen Ceramic University, Jingdezhen 333403, Jiangxi, China;2. Jiangsu Baifu Tech. Co. Ltd., Wuxi 214221, Jiangsu, China)

Abstract: There are different types of Yixing earthenware, while the most representative one is the grey-blue glaze. The grey-blue glaze displays a white ‘tear-stained’ flow pattern on its surface, with the accompany of kiln transformation. The effect of Fe₂O₃ on the structure and coloring of grey-blue glaze was studied and the mechanism of the color variation was analyzed. It is demonstrated that the color of Yixing Jun pottery grey-blue glaze is mainly ascribed to the coupling of structural coloring and Fe³⁺ ion coloring. The droplet sizes at the glaze specimen markings are in the range of 229.80–316.23 nm, which meets the Mie scattering condition. Therefore, the glaze surface at the mottling appears milky white, while the droplet sizes at the base glaze surface around the mottling are 68.83–129.88 nm, which meets the Rayleigh scattering condition, so that the glaze surface appears milky blue. As the Fe₂O₃ content (0 wt.%–7 wt.%) gradually increases, the Fe³⁺ concentration in the glaze increases and the Fe³⁺ coloring ability in the glazed glass is strengthened. As a result, with the coupling of the fractional structural color and ionic coloring, the yellow at the mottling was darkened and the basic blue glaze was partly gradually biased towards blue-green.

Key words: Yixing Jun pottery; grey-blue glaze; fractional emulsion; coloring mechanism