Dynamical neutron-scattering measurements of residual stress in a Si crystal coated with a thin film

The residual stress in a thick Si(111) crystal coated with a 2000 Angstrom thick Ni film was measured at the double-crystal diffractometer at Oak Ridge National Laboratory. The observed asymmetry of the back-face rocking curves and appearance of the garland reflections are related to the ultrasmall deformation strain induced by the Ni film. Relative deformation of the Si crystallographic cells in the vicinity of diffractive surfaces is \ partial derivativeu(z)/partial derivativez \ approximate to1.6.10(-6). The radius of bending is similar to 19 km and the corresponding tension force applied to the Ni film is 90 +/-5 N/m.