The small-angle neutron scattering (SANS) from Fe-Cu-Nb-Si-B nanocryst
alline alloys has been measured in magnetic held. The features of nucl
ear scattering profiles are different from those of the magnetic scatt
ering. The magnetic scattering shows that the distribution of local ma
gnetization is not uniform in a BCC-Fe grain. On the other hand the nu
clear scattering shows that the Omstein-Zernike-type fluctuation of co
ncentration exits in nanocrystalline alloys.