DIFFRACTION OF NEUTRON STANDING WAVES IN THIN-FILMS WITH RESONANCE ENHANCEMENT

Diffraction of neutron standing waves in thin films has been demonstra ted for the first time with experiments on an epitaxial Y/Gd/Y/Nb/Al2O 3 sample. Resonance enhancement in the diffraction intensity has been observed. The new diffraction scheme for neutrons and X-rays provides an oscillatory spatial concentration in thin films, in contrast to the evanescent diffraction which provides an exponential concentration. I t also discriminates against diffraction background from substrate, an d may be especially useful when diffraction in transmission geometry i s not available due to high absorption of substrate.