Indication of intrinsic spin Hall effect in 4d and 5d transition metals

M. Morota, Y. Niimi, K. Ohnishi, T. Tanaka, H. Kontani, T. Kimura, Y. Otani

Published 2010-08-01, updated 2011-05-06Version 3

We have investigated spin Hall effects in 4$d$ and 5$d$ transition metals, Nb, Ta, Mo, Pd and Pt, by incorporating the spin absorption method in the lateral spin valve structure; where large spin current preferably relaxes into the transition metals, exhibiting strong spin-orbit interactions. Thereby nonlocal spin valve measurements enable us to evaluate their spin Hall conductivities. The sign of the spin Hall conductivity changes systematically depending on the number of $d$ electrons. This tendency is in good agreement with the recent theoretical calculation based on the intrinsic spin Hall effect.