Anisotropic magnetothermopower: Contribution of interband relaxation

Spin injection in metallic normal/ferromagnetic junctions is investigated taking into account interband relaxation and the consequences in terms of thermoelectric power. On the basis of a generalized two-channel model, it is shown that there is an interface resistance and thermoelectric power contribution due to anisotropic scattering, besides spin accumulation and giant magnetoresistance. The corresponding expression of the thermoelectric power is derived and compared with the expression accounting for the thermoelectric power produced by the giant magnetoresistance. Measurements of anisotropic magnetothermoelectric power are presented in electrodeposited Ni nanowires contacted with Ni, Au, and Cu. It is shown that a thermoelectric power is generated at the interfaces of the nanowire and that the experimental results strongly support the model.