This article is part of the Journal of Raman Spectroscopy special issue entitled “Raman spectroscopy in art and archaeology” edited by Juan Manuel Madariaga and Danilo Bersani.
The characterization of Sn-based corrosion products in ancient bronzes: a Raman approach†
Article first published online: 10 JUN 2012
Copyright © 2012 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy
Special Issue: Raman spectroscopy in art and archaeology
Volume 43, Issue 11, pages 1596–1603, November 2012
How to Cite
Ospitali, F., Chiavari, C., Martini, C., Bernardi, E., Passarini, F. and Robbiola, L. (2012), The characterization of Sn-based corrosion products in ancient bronzes: a Raman approach. J. Raman Spectrosc., 43: 1596–1603. doi: 10.1002/jrs.4037
- Issue published online: 21 NOV 2012
- Article first published online: 10 JUN 2012
- Manuscript Accepted: 26 JAN 2012
- Manuscript Revised: 10 JAN 2012
- Manuscript Received: 13 DEC 2011
- Raman microscopy;
- bronze corrosion;
- tin oxide;
- copper oxide
The characterization of corrosion patinas on bronzes is preliminarily connected to the determination of proper conservation strategies. Moreover, it also provides an essential contribution to the comprehension of the mechanisms of formation of patinas.
Concerning the last aspect, several studies highlighted that bronze corrosion behaviour cannot be assimilated to that of pure copper. In particular, decuprification and relative enrichment of tin in the corrosion layers were observed. Tin therefore, together with its insoluble salts, plays an important role in the mechanism of formation of bronze patinas. Thus, the characterization of Sn-based corrosion products becomes fundamental, although remaining quite problematic. This work reports several case studies where Sn-based corrosion products grown in bronzes have been identified, thanks to the hyphenated system scanning electron microscopy–energy dispersive spectrometry–Raman structural and chemical analyser. Combining the main characteristics of these techniques, different Sn-containing compounds, mainly crystalline and nano-sized tin dioxides, were detected in bronze patinas exposed to different environments (to the atmosphere, in both natural and accelerated ageing conditions, and to the soil). The main issues regarding the interpretation of Raman spectra of these compounds are presented and discussed. Copyright © 2012 John Wiley & Sons, Ltd.