title: Colouration mechanism of underglaze copper-red decoration porcelain (AD 13th-14th century), China.
abstract: Underglaze copper-red decoration, i.e. the copper colourant used to paint diversified patterns on the surface of a body and then covered by transparent glaze and fired at high temperature in a reductive firing environment, is famous all over the world. However, the red colouration mechanism generated by underglaze copper remains unclear. In particular, the fact that the edges of the red patterns are orange has been ignored in previous research. Here, non-destructive analysis has been carried out on a precious fragment of early underglaze red porcelain using synchrotron radiation X-ray fluorescence, X-ray absorption near-edge spectroscopy (XANES) and reflection spectrometry techniques. The results suggest that the copper content in the red region is higher than that in the orange region, and other colour generation elements do not have obvious content difference, indicating that the colour generation effect of the underglaze red product is related to the copper content. XANES analysis shows that the valence states of copper in the red and orange regions are similar and metal copper contributes to their hues. The results of reflection spectrometry demonstrate that tiny orange hues could be attributed to the Mie scatting effect. Therefore, light-scattering effects should be considered when researching the colouration mechanism of underglaze red.
authors: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China.
authors: Jian
authors: J
authors: Zhu
authors: School of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100083, People's Republic of China.
authors: Huiping
authors: H
authors: Duan
authors: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China.
authors: Yimin
authors: Y
authors: Yang
authors: Jiangxi Provincial Institute of Cultural Relics and Archaeology, Nanchang 330025, People's Republic of China.
authors: Li
authors: L
authors: Guan
authors: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors: Wei
authors: W
authors: Xu
authors: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors: Dongliang
authors: D
authors: Chen
authors: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
authors: Jing
authors: J
authors: Zhang
authors: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China.
authors: Lihua
authors: L
authors: Wang
authors: Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201204, People's Republic of China.
authors: Yuying
authors: Y
authors: Huang
authors: Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China.
authors: Changsui
authors: C
authors: Wang
keywords: XANES; colouration mechanism; reflection spectrometry; underglaze copper-red decoration