Grazing-incidence neutron diffraction by thin films with resonance enhancement

Diffraction of neutron standing waves in thin films has been demonstrated with experiments on an epitaxially grown Y/Gd/Y/Nb/Al2O3 sample. Resonance enhancement in the diffraction intensity has been observed. The diffraction intensity distribution has been well explained within the distorted-wave Born approximation. The effect of surface miscut and mosaic spread has been incorporated in the quantitative calculation. In general, the proposed diffraction geometry for thin films equally applies for x rays. In contrast to traditional diffraction geometries, the proposed one discriminates against substrate diffraction, provides certain spatial resolution within the film sample, and may be particularly useful when the conventional diffraction geometries for thin films do not apply.