The Self-Diffusion of Copper

Abstract

The self-diffusion of copper has been measured with a radioactive isotope prepared by neutron bombardment of zinc. The isotope is electroplated in a thin layer upon the surface of a copper disk. By measuring the decrease in $\beta$-ray emission from the sample due to the penetration of the radioactive copper, the self-diffusion constant is determined within the limits of accuracy as 11 ${\mathrm{cm}}^2$/sec. $\exp (-\frac{57,200}{\mathrm{RT}})$. Methods of analyzing such data are given and the significance of the variation of activation energy between self-diffusion and heterogeneous diffusion is discussed.