Using low-energy electron microscopy, the diffusion of Pd into bulk Cu at the Cu(100) surface was measured. Interdiffusion was tracked by measuring the dissolution of the Cu(100)–c(2 x 2)-Pd surface alloy during annealing (T>240C). The activation barrier for Pd diffusion from the surface alloy into the bulk was determined to be (1.8 ± 0.6)eV. During annealing, the growth of a new layer of Cu near step edges was observed. Under this new Cu layer, dilute Pd remaining near the surface develops a layered structure similar to the Cu3Pd L12 bulk alloy phase.

Palladium Diffusion into Bulk Copper via the (100) Surface. E.Bussmann, J.Sun, K.Pohl, G.L.Kellogg: Journal of Physics - Condensed Matter, 2009, 21[31], 314016