Glass and Ceramic for the Arts

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Publications

An insight into the firing conditions of Chinese blue-and-white porcelain through XANES

Publication . Coutinho, ML; Veiga, JP; Ruivo, Andreia; Silva, Teresa; Salas-Colera, Eduardo; Bottura Scardina, Silvia; Lima, Augusta; Figueiredo, Elin; Cotte, Marine; Lima, M.M.R.A.

ABSTRACT: Chinese blue-and-white porcelain is found in archaeological excavations worldwide, being significant evidence of global trade routes and cultural exchange. Synchrotron radiation-based techniques have been applied for studying cobalt speciation to establish a correlation between the cobalt and iron oxidation state and local coordination environment in the rich blue shades of Chinese blue-and-white porcelain. However, the relationship between the firing atmosphere conditions and the speciation of cobalt has not been established yet. In this study, underglaze blue models were produced and fired in air or under reducing atmospheres to ascertain the effect of the firing atmosphere in cobalt and iron speciation. The experimental results were compared with data obtained on historical samples of ancient porcelain shards. The microstructure and colour of the produced underglaze blue models were investigated by variable pressure scanning electron microscopy (VP-SEM-EDS), using a hyperspectral imaging camera (Vis-SWIR reflectance spectroscopy) and colorimetry. The formal valence and coordination of cobalt and iron ions of the glaze were determined by X-ray absorption spectroscopy (XAS), particularly X-ray absorption near edge structure (XANES), using synchrotron radiation. Spectral features demonstrated that both cobalt and iron speciation were affected by the firing atmosphere and therefore could be used to ascertain the firing atmosphere.

2022-02Journal article

Embargoed access

Cultural Heritage analysis using Synchrotron Radiation: case studies in Ceramics, Glasses, and Lithologic Materials

Publication . Veiga, JP; Coutinho, ML; Figueiredo, Elin; Silva, Teresa

ABSTRACT: Synchrotron radiaton is a powerful tool for non‐destructve analysis of materials in cultural heritage research. It has revolutonized our ability to understand the compositon, structure, and history of cultural heritage objects, leading to significant advances in fields such as archaeology, art conservation, and materials science. Dedicated beamlines for cultural heritage research are available at synchrotron facilites around the world, such as the European Synchrotron Radiation Facility (ESRF), SOLEIL synchrotron, and ALBA synchrotron, providing specialized support and instrumentation for high‐resolution analysis of cultural heritage objects using various techniques, such as X‐ray absorption spectroscopy, X‐ray fluorescence, X‐ray diffraction, and X‐ray imaging.

2023-07Conference object

Open access

The materials of historical monuments: characterisation of the mortars of the Roman aqueduct of Zaghouan-Carthage

Publication . Carvalho, Fernanda; Lima, Maria Margarida Rolim Augusto; Silva, Teresa; Veiga, João Pedro

ABSTRACT: The Zaghouan-Carthage Roman aqueduct was the largest built by the Roman Empire at the time, and its archaeological remains bear witness to the excellence of Roman construction. Its importance over the centuries makes it a unique case study for characterising the different types of mortar used. This work aims to study these materials, considering their functions, especially as structural elements or as render, to relate the chemical and mineralogical characteristics observed to both the function and historical context of the monument. Using a multi-analytical approach, the preservation of samples was prioritised whenever possible. The results indicate that mortars with a structural function have higher silicon contents than those used as render. In the case of water conduit coatings, the mortars were formulated with ground ceramics to develop hydraulic properties and ensure the waterproofing material. However, it was not possible to identify a characteristic pattern related to the historical construction periods.

2025-12Journal article

Open access