The results of the first observation of the small-angle polarized neut
ron scattering (SAPNS) from magnetic flux inhomogeneities in high-T-c
Y-Ba-Cu-O and La-Sr-Cu-O ceramics are reported. The difference between
the scattering cross sections for neutrons initially polarized along
or opposite to the applied field was found at T < T-c and in the range
of applied field below H-c1 of grain in ceramics. The alternative sig
n effect was observed in remanent field trapped in grains after applyi
ng a field. The effect is explained by nuclear-magnetic interference a
nd is proportional to the Fourier transform of the cross-correlator of
the magnetic-nuclear (MN) scattering length density fluctuations (SLD
).