Fe speciation in multiphase assemblages of black and white porcelain (Jin dynasty 1115-1234 CE) using micro-X-ray Absorption spectroscopy

Abstract

Black and white porcelain is a highly heterogeneous multilayer ceramic system, whose technological information and microstructure are influenced by the raw materials composition and complex reactions that occur during the firing process. This study performed several synchrotron radiationbased analytical techniques (μ-XRF mapping, μ-XANES spectra, μ-XANES mapping, and SIXES) to analyze the spatial distribution of major elements in the stratigraphic layers, as well as the spatial distribution of iron speciation.The results show that the pigment sources are diverse, including iron-rich glazes, iron-bearing clay minerals, and non-clay iron minerals. Pigment particles, mainly composed of hematite, play a key role in the formation of decorations. In addition, the valence state of iron among layers is not stable and even exhibits differences at the micrometre scale. Our results also indicate that the multi-technique approaches based on synchrotron-radiation have significant advantages on studying complex layered ceramic systems, especially the μ-XANES mapping and SIXES techniques, which provide information on iron species and their local variations while maintaining micrometre scale spatial resolution.