IBE-XPS investigation of the gilded layer from the Eastern Han Dynasty naturally corroded gilt-bronze

The gilded layers from the Eastern Han Dynasty (AD 25–220) naturally corroded gilt-bronze were studied by means of combined ion beam etching X-ray photoelectron spectroscopy (IBE-XPS), scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDX) and element mapping. It is the first time ancient Chinese gilded layers were analyzed in order to study the valence and ion migrations in the oxidized gilding layer’s intermediate layer. The results showed that Au, Ag, Cu and Sn were the major components of the gilded layer with severely oxidation. Au was extant in Au (0) form, Ag migrated would gather in the surface of the gilded layers in Ag (I) form, copper and tin prepared in the gilded layers were migrated from the bronze, copper was extant in Cu (II) and Cu (I) form, tin was extant mostly in the form of in Sn (IV) with a little Sn (II) in the interlayers.