  We present the experimental results for Nb/Au/YBaCuO structures, in which the
current flows along (001) direction of YBaCuO film. The theoretical evaluations
show, that at the experimental values of the Au/YBaCuO interface transparency,
determined from the interface resistance D~10^-6, the critical current of the
structure is of the fluctuation order of magnitude due to the sharp decrease of
the amplitude potential of the superconducting carriers on this interface.
Obtained I-V-curves could be interpreted in terms of contact between d-type
pairing superconductor or gapless isotropic superconductor with normal metal.
No critical current was observed for investigated structures with
characteristic interface resistance RnS~10^-6 Ohm cm^2, 2 orders of magnitude
lower, than for known experimental data. PACS: 74.50.+r, 74.72.Bk
