Microstructural characterization of the NdBa2Cu3O7−δ islands fabricated by liquid phase epitaxy

Abstract NdBa 2 Cu 3 O 7− δ (NBCO) islands were grown on MgO substrate by liquid phase epitaxy (LPE). The microstructures of NBCO islands ranging from 4.5 to 48 μm in lateral length were investigated in detail by cross-sectional transmission electron microscopy and energy-dispersive X-ray analysis. Most islands exhibit epitaxial relationship, {0 0 1} NBCO //{0 0 1} MgO , which will lead to the growth of c -axis epitaxial NBCO film. It was revealed that the NBCO islands grow laterally and some Ba–Cu–O fluxes are entrapped between NBCO and MgO substrate. The growth mechanisms of the NBCO islands by LPE were discussed in terms of two growth modes. One is coarsening, which results in no grain boundary, the other is coalescence. Furthermore, the formation of flux-entrapping was discussed.