Resistivity measurements were made of a single grain boundary in zone-refined material at 4.2K by using superconducting quantum interference devices. This revealed that the intrinsic grain boundary resistivity depended upon the boundary structure. It was concluded that the grain boundary resistivity was caused mainly by electron scattering from the dislocation core region of the boundary. A grain-boundary resistivity equation that was based upon a dislocation model explained the rotation-angle dependence of the resistivity for low-angle, high-angle and coincidence-related boundaries. This suggested that the Read-Shockley model could be applied to these boundaries, in view of the dislocation core overlap. Measurements that were performed on Ag-containing alloys demonstrated that migrating grain boundaries were associated with a much greater solute enhancement than equilibrium segregation. It was suggested that the solute resistivity became an order of magnitude lower when the solute segregated about grain boundaries.

I.Nakamichi: Materials Science Forum, 1996, 207-209, 47-58