Misfit dislocations in highly mismatched oxide interfaces, an X-ray diffraction study

International audienceWe present here a detailed study describing the strain relaxation mechanisms occurring in the highly mismatched ZrO2/MgO system. Especially, we show using reciprocal space mapping that the ZrO2 islands epitaxially grown on the MgO substrate are fully relaxed implying the formation of misfit dislocations at the interface. Furthermore, an analysis of transverse scans performed through symmetrical ZrO2 reflections for several azimuthal positions of the sample lets us conclude that dislocations form a square network parallel to ZrO2 cell axes. Finally, an accurate analysis of the diffraction data evidences the existence of two subsets of misfit dislocations