Angle dependence of Jian bowl color and its coloring mechanism

Abstract Jian bowl is generally known for its artistic appearance such as hare's fur and oil spots caused by the crystallization of iron oxides on the glaze surface. While very few Jian bowls have angle-dependent colors, scientific research on the topic is lacking owing to the scarcity of relevant samples. In this study, the angle-dependent colors of Jian bowls were systematically studied using various characterization techniques, such as angle-resolved reflectance spectra, X-ray diffraction, micro-Raman, field emission scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The angle dependence phenomenon of Jian bowl colors was classified into two types, and the coloring mechanisms were clarified. The first type of coloring mechanism is assumed to be coherent light scattering by an amorphous photonic structure formed during the firing process, which has weak angle dependence. The second type of coloring mechanism is thin-film interference, which has obvious angle dependence and is closely related to the corrosion process of Jian bowls in the burial environment.