The diffusion coefficient was measured by performing diffusion-couple experiments at temperatures ranging from 1223 to 1378K, or by performing anelastic relaxation experiments at temperatures ranging from 430 to 460K. The couples were made up of Pd and Pd-C alloys, where the C-content was 0.7 or 1.4at%. The resultant diffusivities ranged from 5.0 x 10-11 to 2.05 x 10-10m2/s. The activation energy for diffusion at the higher temperatures was 132kJ/mol. It was found that the results which were obtained for these 2 temperature regions were in reasonable agreement with each other. The diffusion of C in Pd was faster than in Ni, Co or γ-Fe.

The Solubility and Diffusion of Carbon in Palladium H.Yokoyama, H.Numakura, M.Koiwa: Acta Materialia, 1998, 46[8], 2823-30