Dating archaeological copper using electrochemical impedance spectroscopy. Comparison with voltammetry of microparticles dating.

摘要

A methodology for dating copper/bronze archaeological objects aged underatmospheric environments using electrochemical impedance spectroscopy(EIS) is described. The method is based on the measurement of resistanceassociated to the growth of corrosion layers in EIS recorded upon immersion ofthe pieces in mineral water and applying a bias potential for the reduction ofdissolved oxygen. Theoretical expressions for the time variation of suchresistance following a potential rate law are presented. Equivalent expressionsare derived and applied for estimating the variation of the tenorite/cuprite ratiofrom their specific voltammetric signals using voltammetry of microparticlesdata. Calibration curves were constructed from a set of well-documented coins.