The role of grain boundaries in the electrical resistance of submicron grained nickel

An investigation is made of highly strained nickel with a purity of 99.99%. The formation of the submicron grained (SMG) structure is studied by transmission electron microscopy. The density of extrinsic grain boundary dislocations (EGBD) is measured. The microdistortions in the samples are investigated by X-ray analysis. The electrical resistance of SMG nickel is studied as a function of grain size. The coefficient of mirror reflection of conduction electrons from grain boundaries is found to be 0.38. An increase of microdistortions and of the high EGBD density in samples annealed above Tc are observed. These phenomena affect the shape of the electrical resistance curve as a function of the annealing temperature. (orig.)