Diffraction des rayons X sur couches minces polycristallines ou epitaxiees. Utilisation d'un montage en reflexion asymetrique equipe d'un detecteur courbe a localisation

摘要

We have realised an X-ray diffraction apparatus with a four-axis sample holder working under controlled incidence in the reflection mode. The incident beam, supplied by a rotating anode associated with a Bartels monochromator, is strictly parallel and monochromatic. The diffracted beams were simultaneously measured using a curved position sensitive detector. The use of this diffractometer in powder diffraction experiments has been presented elsewhere. In this paper we would illustrate the possibility of such an apparatus in the field of thin film characterization. Thin films of zirconia precursor were formed on mirror-polished sapphire wafers by a sol gel dip coating process. Thermal treatment of the sample at moderated temperature induced the crystallisation of zirconia under the teragonal form. The coating is made of randomly oriented nanocrystals. Higher temperature thermal treatment resulted in the formation of micrometer sized islands epitaxied onto the single crystalline substrate. The relative disorientation of those islands was estimated through rocking-curves measurements. Sometimes the diffracted intensity distributions of the different island families were partially superimposed on each others. The measurement of all the intensity distributions obtained by