A Calculation of the Formation and Migration Entropies of Surface Defects in Copper

Formation entropies, frequency factors, and associated migration entropies have been calculated on copper surfaces of (100), (110), and (111) orientations for both terrace vacancies and adatoms, using a discrete vibrational approach. The vibrational spectra for the various defect configurations have been obtained using a quasi‐harmonic Einstein model in conjunction with a modified Morse function force law. ‐ The calculated quantities have been used to estimate Arrhenius D 0 's for intrinsic, single‐defect‐controlled diffusion. When these quantities are taken together with previously calculated activation energies for surface self‐diffusion, it is possible to obtain theoretical Arrhenius plots for each defect on a given surface orientation. The results are also helpful in the evaluation of earlier mechanistic interpretations of the observed curvature in the experimental Arrhenius plots.