Silver and copper nanoclusters in the lustre decoration of Italian Renaissance pottery: an EXAFS study

Abstract

Lustre is one of the most important decorative techniques of the Medieval and Renaissance pottery of the Mediterranean basin, capable of producing brilliant metallic reflections and iridescence. Following the recent finding that the colour of lustre decorations is mainly determined by copper and silver nanoclusters dispersed in the glaze layer, the local environment of copper and silver atoms has been studied by extended X- ray absorption fine structure (EXAFS) spectroscopy on original samples of gold and red lustre. It has been found that, in gold lustre, whose colour is attributed mainly to the silver nano- cluster dispersion, silver is only partially present in the metallic form and copper is almost completely oxidised. In the red lustre, whose colour is attributed mainly to the copper nanocluster dis- persion, only a fraction of copper is present in the metallic form. EXAFS measurements on red lustre, carried out in the total elec- tron yield mode to probe only the first 150 nm of the glaze layer, indicated that in some cases lustre nanoclusters may be confined in a very thin layer close to the surface

Metallic and nonmetallic shine in luster: An elastic ion backscattering study

“…Similar results have been found for medieval lusters. 4,[11][12][13] EIBS analysis of both the glaze luster free surface and the luster layers have been performed for the three glaze compositions and corresponding luster layers, and are shown in Figs. 3-5, respectively, and the corresponding composition depth profiles are shown in Fig.…”

“…10 In particular, their color ͑typically red, brown, green, yellow, and amber͒ depends mainly on the nature and size of the metal nanoparticles ͑Cu and/or Ag͒ and the presence of ions ͑Cu + and Cu 2+ ͒ dissolved in the glass structure. [11][12][13] In addition, one of the most striking properties of luster is its capability of reflecting light like a metal surface. For example, a green luster layer may show a gold-like shine, 6 but it is also possible to have a dark brown luster showing also a gold-like shine.…”

Composition, nanostructure, and optical properties of silver and silver-copper lusters

“…The presence of cuprite (Cu 2 O) nanoparticles (absorption at about 520 nm) and of copper ions (Cu þ and Cu 2þ ) dissolved in the glass modifies the color shown by the luster layers. 11,12 Finally, increasing the size of the metal nanoparticles or the refraction index of the glassy matrix red shifts the SPR absorption bands and, consequently, also varies the color of the luster layer.…”

Study on Coloration Mechanism of Chinese Ancient Ceramics by X-ray Absorption Near-edge Structure

“…With the increase of production, the prosperity of the government porcelain kilns greatly promoted the porcelain baking technology. To reveal the information about the production technology, numerous researches have been focused on the color-generating elements in ancient ceramics glaze among which chemical structure analyses of the transition elements is most popular [2][3][4][5]. Therefore, amounts of advanced scientific techniques are used to investigate the archaeological materials.…”

“…Mössbauer spectroscopy and Neutron activation analysis (NAA) reveal that the different coloration on the glaze is originated from the conditions of production processes [9][10]. Also, synchrotron radiation technologies, such as SRXRF and XANES, have been applied in porcelain structure analysis [5,[11][12]. However, the production of porcelain involved roughly the raw materials, a delicate refinement procedure, and a developed firing technology, so there is no uniform interpretation on the color-generating mechanism for different typical porcelain.…”