New X-ray diffraction equipment for analysis of mechanical states (stress and microdeformation) of thin nanocrystalline films

The mechanical state in thin films very much influence their physical properties. The knowledge of residual stresses and microstresses in these materials is therefore very important. Classical methods of X-ray diffraction (sin(2) psi and integral width or Warren-Averbach) are difficult to apply in such materials because the diffracted intensities are weak due to the nanocrystalline structure of these films. In order to solve these difficulties, we developed an original X-ray diffraction set-up. Its main features are the followings: intense Xray source (synchrotron radiation or rotating anode), incident and diffracted x-ray path under vacuum, and recording of the spectrum with a proportional sensitive detector. Results obtained for 304L stainless steel and Cu-Mo thin films show the full potentialities of such an equipment.