Characterization of elemental composition in a 4th century AD ancient coin using micro-pixe analysis with four-channel SDDs

Abstract

The study of elemental composition in cultural heritage objects, such as ancient coins, provides valuable insights for archaeologists into the historical, geographical, and political contexts of these artifacts. Additionally, analyzing constituent elements and their changes over time is vital for implementing preservation measures. This article examines the composition and concentration of constituent elements in a Roman coin dating back to the 4th century AD. Micro Particle‐Induced X‐ray Emission (micro-PIXE) analysis utilizing annular four-channel Silicon Drift Detectors (SDDs) proves to be an effective technique for studying coin surfaces, offering non-destructive analysis, large solid angle detection, limited penetration depth, and multi-element distribution detection capabilities. Investigations across different regions of the coin revealed major concentrations of (Cu) at 37.41 ± 2.15%, (Pb) at 32.18 ± 1.40 %, and (Sn) at 18.81 ± 1.61%. Notably, the detected elements (Al, Si, P, Cl, K, Ca, and Ti) exhibited significant difference levels likely attributed to the burial environment. Furthermore, two-dimensional elemental distribution maps of major and minor elements were generated using the four- channel SDDs. Subsequent washing of the coin with acetic acid resulted in a notable decrease in Pb and Sn concentrations, indicating their presence primarily within the surface patina layer. Additionally, the detected elements were compared with X-ray fluorescence analysis.