NEW X-RAY-DIFFRACTION EQUIPMENT FOR ANALY SIS 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 th ese materials is therefore very important. Classical methods of X-ray diffraction (sin(2) psi and integral width or Warren-Averbach) are dif ficult to apply in such materials because the diffracted intensities a re weak due to the nanocrystalline structure of these films. In order to solve these difficulties, we developed an original X-ray diffractio n set-up. Its main features are the followings: intense Xray source (s ynchrotron 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-M o thin films show the full potentialities of such an equipment.