  Nonlinear current-voltage characteristics and magnetoresistance of point
contacts between a normal metal (N) and films of amorphous ferromagnet (F)
Co40Fe40B20 of different thickness, exchange-biased by antiferromagnetic
Mn80Ir20 are studied. A surface spin valve effect in the conductance of such
F-N contacts is observed. The effect of exchange bias is found to be inversely
proportional to the Co40Fe40B20 film thickness. This behavior as well as other
magneto-transport effects we observe on single exchange-pinned ferromagnetic
films are similar in nature to those found in conventional three-layer
spin-valves.
