Electron mean free path in elemental metals

The electron mean free path lambda and carrier relaxation time tau of the twenty most conductive elemental metals are determined by numerical integration over the Fermi surface obtained from first-principles, using constant lambda or tau approximations and wave-vector dependent Fermi velocities v(f) (k). The average v(f) deviates considerably from the free-electron prediction, even for elements with spherical Fermi surfaces including Cu (29% deviation). The calculated product of the bulk resistivity times lambda indicates that, in the limit of narrow wires, Rh, Ir, and Ni are 2.1, 1.8, and 1.6 times more conductive than Cu, while various metals including Mo, Co, and Ru approximately match the Cu resistivity, suggesting that these metals are promising candidates to replace Cu for narrow interconnect lines. (C) 2016 AIP Publishing LLC.