Grain-boundary self-diffusion in Pb

We have carried out self-diffusion studies along grain boundaries in polycrystalline Pb specimen in the temperature range of 70-200°C. Pb 203 radioactive isotope (half life of 52.1 h) was used as a tracer, and precision microtome serial sectioning and high-efficiency gamma counting techniques were employed. The combined diffusion parameter δDb in Pb grain boundaries is expressed by the Arrhenius relation δD b=(6.1±0.9)×=10-9 exp(-0.46±0.01 eV/kT)(cm3/sec).