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

We 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. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)