We present a study of the influence of an external magnetic field H and an electric current I on the spin-valveud(SV) effect in point contact between a ferromagnetic thin film (F) and a sharp tip of a nonmagnetic metal (N). Toudexplain our observations, we propose a model of a local surface SV which is formed in such a N/F contact. Inudthis model, a ferromagnetic cluster at the N/F interface plays the role of the free layer in this SV. This cluster exhibitsuda larger coercive field than the bulk of the ferromagnetic film, presumably due to its nanoscale nature. Finally,udwe construct a magnetic state diagram of the surface SV as a function of I and H.
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