Neutron diffraction study of nanocrystalline NbC$_{0.93}$ powders and the anisotropy of deformation distortions

Broadening of the diffraction reflections in nanocrystalline powders of nonstoichiometric niobium carbide NbC$_{0.93}$ with the average particle size from $\sim200$ to $\sim2000$ Åhas been studied by the neutron diffraction method. The functional dependence of the broadening $W^2$ on the interplanar distance $d^2$ has been obtained including size, deformation, and inhomogeneous broadening. The average size of the coherent scattering regions and microstrains in crystallites with allowance for the anisotropy of the deformation distortions have been estimated.