Nonlinear current-voltage characteristics and magnetoresistance of pointcontacts between a normal metal (N) and films of amorphous ferromagnet (F)Co40Fe40B20 of different thickness, exchange-biased by antiferromagneticMn80Ir20 are studied. A surface spin valve effect in the conductance of suchF-N contacts is observed. The effect of exchange bias is found to be inverselyproportional to the Co40Fe40B20 film thickness. This behavior as well as othermagneto-transport effects we observe on single exchange-pinned ferromagneticfilms are similar in nature to those found in conventional three-layerspin-valves.
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