Abstract
Residual resistivity at 4 K has been studied as a function of grain boundary area per unit volume in aluminium of two differing purities. A positive correlation between residual resistivity and boundary area was observed above a minimum boundary area per unit volume. The resistivity attributable to the presence of grain boundaries was found to reflect both the defect structure of the boundaries and the solute redistribution due to boundary segregation. Elimination of the solute effect yielded a specific boundary resistivity of 1·35±0·5 × 10−12 ohm-cm2 for pure boundaries. Evidence of a purification effect due to grain boundary segregation was noted.