Low temperature transport properties of nanocrystalline Cu, Fe and Ni

The electrical resistivity and thermoelectric power were measured of nanocrystalline high purity 4N copper, nickel and iron prepared by torsional deformation at quasihydrostatic pressure of 6 GPa. The resistivity was found to be 15 to 55% higher than for the polycrystalline metals. This reveals that the transport phenomena in the nanocrystalline state of Cu, Ni and Fe are strongly influenced by the electron scattering on the grain boundaries in agreement with the Mayadias-Shatzkes model. The structural disorder in the nanocrystalline metals reduces the electron-phonon interaction more than it reduces the magnon-phonon interaction.