Published online by Cambridge University Press: 31 January 2011
The film crystallinity and nature of the interface between Y1Ba2Cu3O7−x (YBCO) films and (100)-oriented MgO substrates are revealed using results from x-ray line broadening analysis, x-ray pole figure analysis, and simple models for interface types. The superconductor film was grown using Activated Reactive Evaporation (ARE) at 675 °C. The results show that the interface can be treated as semicoherent with interfacial dislocations whose spacing depends on the in-plane orientation relationship between YBCO and MgO. For the orientation relationship (100) YBCO parallel to (100) MgO, the spacings between dislocations are 9 lattice spacings of MgO in the a direction and 11 lattice spacings of MgO in the b direction. For the orientation relationship (110) YBCO parallel to (100) MgO, the spacing between dislocations is 2 lattice spacings of MgO (or 4 plane spacings of (200) MgO—see Ref. 10). The x-ray based method used here can be an addition to or a replacement for the cumbersome cross-sectional TEM technique (for the YBCO system) to view the interface.