Micro-Raman Characterisation of Silver Corrosion Products: Instrumental Set Up and Reference Database

While several databases with Raman spectra of interest to silver corrosion have been published already, we present a catalogue of Raman spectra of silver compounds, which can be found on corroded silver and silver alloy objects, i.e. not only concerning archaeological and artistic works but all kind of silver items exposed to the atmosphere. The collected Raman spectra of these highly pure (>99.99%) silver compounds have been useful as references in a project concerning the identification of silver corrosion products by micro-Raman spectroscopy in the early stages of atmospheric corrosion. The instrumental conditions and parameters, the most representative spectrum, and band assignments are reported for each selected silver compound followed by some detailed comments, unlike many other collections of spectra. Since some of these compounds show low vibrational frequencies and are highly photo-sensitive, micro-Raman spectroscopy has revealed to be a suitableand non-destructive tool for their analytical characterisation.