Diffusion of Radioactive Copper during Oxidation of Copper Foil

Abstract

Strips of copper foil were plated with a thin deposit of radioactive copper and the specimens then oxidized in air at 800°, 900°, 1000°C. From the distribution of radioactive copper in the oxide diffusion coefficients, D, for cuprous ion in cuprous oxide were calculated. Over the temperature range D was found to be 0.0358 exp(−37,000/RT) cm² sec.⁻¹. The activation energy for the oxidation of copper is 39±2 kcal./mole, so that these measurements provide further evidence that diffusion of Cu⁺ in Cu₂O is the rate‐determining step in the oxidation.