Auger electron spectroscopy was used to measure the concentration profiles of Cu. After annealing at between 500 and 800C, the lattice and grain boundary diffusivities were extracted from the concentration profile on the basis of a Whipple analysis of grain boundary diffusion. The values obtained followed an Arrhenius dependence from 500 to 800C :

Grain-boundary:    D(cm2/s) = 3.60 x 10-12 exp[-0.50(eV)/kT]

Lattice:     D(cm2/s) = 1.67 x 10-17 exp[-0.21(eV)/kT]

J.C.Lin, C.Lee: Electrochemical and Solid-State Letters, 1999, 2[2-4], 181-3