Published online by Cambridge University Press: 26 February 2011
Grain boundary chemical diffusivities for a series of symmetric [001] tilt boundaries in the Au/Ag system were measured by the surface accumulation method using newly developed thin-film multi-crystal specimens, in which the grain boundaries feeding the accumulation surface were all of the same type. Possible effects due to segregation at the grain boundaries and surfaces were avoided. CSL boundaries of low-Σ ( i.e., 5, 13, 17, 25) and also more general boundaries with tilt angles between the low-Σ orientations were selected. The diffusivities were found to vary monotonically with tilt angle ( i.e., no cusps at low-Σ's were found) in a manner consistent with the Structural Unit model.